- Email: [email protected]
Efficient natural piezoelectric nanogenerator: Electricity generation from fish swim bladder
Author’s Accepted Manuscript Efficient Natural Piezoelectric Nanogenerator: Electricity Generation from Fish Swim Bladder Sujoy Kumar Ghosh, Dipankar Mandal
www.elsevier.com/locate/nanoenergy
PII: DOI: Reference:
S2211-2855(16)30319-6 http://dx.doi.org/10.1016/j.nanoen.2016.08.030 NANOEN1443
To appear in: Nano Energy Received date: 6 June 2016 Revised date: 2 August 2016 Accepted date: 10 August 2016 Cite this article as: Sujoy Kumar Ghosh and Dipankar Mandal, Efficient Natural Piezoelectric Nanogenerator: Electricity Generation from Fish Swim Bladder, Nano Energy, http://dx.doi.org/10.1016/j.nanoen.2016.08.030 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Efficient Natural Piezoelectric Nanogenerator: Electricity Generation from Fish Swim Bladder
Sujoy Kumar Ghosh, Dipankar Mandal*
Organic Nano-Piezoelectric Device Laboratory, Department of Physics. Jadavpur University, Kolkata 700032, India *
Corresponding author. Tel.: +91 33 2414 6666x2880; fax: +91 33 2413 8917.
[email protected]
Abstract An efficient bio-piezoelectric nanogenerator (BPNG) is fabricated from the fish swim bladder (FSB), composed of well-aligned natural collagen nano–fibrils. The self-alignment of highly ordered structure in the FSB collagen has been confirmed by angular dependent near edge X-ray absorption fine structure (NEXAFS) spectroscopy. Compressive normal stress by human finger can able to drive the BPNG that generates an open-circuit voltage of 10 V and short-circuit current of 51 nA. The generated electricity from the FSB instantly turns on more than 50 commercial blue light emitting diodes (LEDs), indicates to use as a sustainable power source in portable electronic devices where the bulky battery counterpart can be avoided. The instantaneous piezoelectric power generation (~ 4.15 μW/cm2) and substantial energy conversion efficiency (~ 0.3 %) of BPNG promises an emerging application, particularly to built self-
powered biomedical sensors because collagen itself one of the most abundant protein available in human body.
Graphical Abstract Green and clean energy harvesting via fabrication of a bio-degradable and bio-compatible piezoelectric nanogenerator i.e., bio-piezoelectric nanogenerator (BPNG) from waste fish byproducts is spot lighted through one step process.
Keywords fish swim bladder, natural piezoelectric material, bio-piezoelectric nanogenerator, collagen nano fibrils, mechanical energy harvester, self-powered biomedical sensor
1. Introduction A self-powered system allows the in-situ, real time biomedical health monitoring. Among currently available technologies, piezoelectric materials based self-powered nanogenerators (NGs) have attracted rapid growing interest as a new kind of energy source due to the applicability as biomedical devices and suitability in flexible portable electronics [1-8]. Several efforts have been made to fabricate NGs based on several piezoelectric materials such as ZnO [2], PMN-PT [3], ZnSnO3 [4], BaTiO3 [5], PZT [6], and synthetic polymers (e.g., PVDF and its copolymers) [7,8]. To adapt a self-powered system as an implantable biomedical device, such as artificial cardiac pacemaker, the material used for the energy harvesting system is the most
important issue, because under in vivo monitoring condition even a very low level of toxicity originating from the self-powered system can cause heart failure and harm the patient. Thus, a biomaterial based self-powered system is the alternative to overcome this long standing challenge. The most easily available biomaterial possessing intrinsic piezoelectricity is the collagen fibril, which is also bio-degradable, bio-compatible and abundantly present in animal tissues such as skin, tendon, cartilage, bone and even in human heart itself [9,10]. Animal skins dominantly contain type I collagen. It is composed of three polypeptide chains (α-chain), two identical α1(I) chains and a different α2(I) chain. Each of them consists of repeated triplet amino acid motif sequences of Gly (Glycine)-X-Y, in which X and Y are frequently proline (Pro) and hydroxyproline (Hyp), respectively [11]. The three α-chains twist together into a unique triplehelical structure. The collagen monomers comprise of such a long helical region in length and short non-helical N and C-terminal telopeptides. The quarter staggered arrangement of the collagen molecules contributes to collagen fibrils with a characteristic axial periodic structure, and the fibrils further assemble into a collagen fiber [12,13]. The hydrogen bond formation between the polypeptide chains plays the essential role for the piezoelectricity. The intrinsic presence of the polar uniaxial orientation of molecular dipoles causes polarization and the piezoelectricity which makes the collagen to become a natural electret or bioelectret material as well [14-19]. To date, very few attempts have been undertaken to explore the potential applications of the naturally occurring electret materials [18-21], and this is the first attempt where the applicability of bio-piezoelectric nanogenerator (BPNG), fabricated directly from fish swim bladder (FSB) is demonstrated. In this approach, we directly use fish (Catla Catla, a fresh sweet water fish) swim bladder (mainly a waste product in fish processing) composed of naturally well aligned collagen nano-
fibrils to fabricate a BPNG. As a direct proof of evidence, dipolar orientation persisting in FSB collagen is exclusively confirmed by angular dependent NEXAFS study. The BPNG exhibits an open-circuit voltage (VRoc) of 10 V and a short-circuit current (IRsc) of 51 nA under repeated periodic compressive normal stress (~ 1.4 MPa) imparted by human finger. Our BPNG is able to deliver an output power density of 4.15 μW/cm2 with superior piezoelectric energy conversion efficiency (~ 0.3 %) which is demonstrated to power up several colour light emitting diodes (LEDs) such as 50 blue, 22 green as well as red and white LEDs that pave the way for potential application in portable electronics and implantable biomedical sensors. 2. Experimental 2.1. Collection of the fish swim bladder The fish swim bladder used in the experiments was collected from nearby Jadavpur University market. The FSB is basically thrown away during food processing. It was cleaned by de-ionized water and subsequently dried in room temperature. Then it was cut into rectangular shape (17.5 mm × 13.5 mm) for entire experiments. It should be noted that no live animal experiments have been performed. The average thickness of the FSB was 253±10 µm measured by digital slide caliper (CD-6''VC, Mitutoyo) and cross checked from cross-sectional FE-SEM images. 2.2. Electrical measurements At first, the gold (Au) electrode with 90 nm of thickness was deposited on both sides of FSB at room temperature with specific operating conditions such as, deposition rate of 0.13 nm/s, 0.1 mTorr of working pressure, 2.5 kV of applying voltage, 20 mA of current and the target to specimen distance of 50 mm. The temperature arises during Au sputtering is of less than 1 oC which does not affect the collagen crystals of FSB. After Au sputtering, the FSB was still
flexible which is demonstrated in Figure 1c. The dielectric properties of the FSB with Au sputtered electrodes were measured in the frequency range from 100 Hz to 1 MHz at room temperature using a precision impedance analyzer (Wayne Kerr, 6500B). The d 33 value of the same FSB was measured by d33 meter (Piezotest, PM300) in HI/d33 mode (where capacitance, C measurement of the material is inactive) under the constant applied force of 0.4 N and frequency at 110 Hz after calibrating the instrument with a piezoMeter reference sample whose d33 value is 349 pC/N. 2.3. Nanogenerator Fabrication To fabricate the robust nanogenerator (BPNG), the gold sputtered FSB (with effective area, A~ 217 mm2 and thickness, t~ 253 μm) was attached with fine copper wires by means of silver paste. Finally, the FSB was encapsulated with PDMS (Sylgard, 184 SILICONE ELASTOMER) layer, prepared by 10:1 curing agent and cured in an oven at 60oC for 30 m. The final cured thickness of PDMS layer is about 1 mm i.e., total thickness of the BPNG is 1 mm including FSB. Thus, the thickness of the PDMS layer on either side of the FSB is 374 µm. The dimension of the BPNG was kept
.
2.4. BPNG performance characterization The output performance of the BPNG has been investigated by periodical human finger imparting vertically to the electrodes (Figure 4a). To demonstrate the stress ( ) dependent VRoc and IRsc, the human finger was impacted from different heights (Table S1) to generate several stresses, maintaining an average frequency of ~ 6 Hz. The output voltage and current from the BPNG under several stresses were recorded with a digital storage oscilloscope (Agilent DSO3102A) and digital pico-ammeter (DPA 111) respectively.
2.5. Materials characterizations The UV-vis absorption spectrum was recorded by spectrophotometer (3110PC, Shimadzu). To investigate the detailed surface morphology, Field Emission Scanning Electron Microscopy (FEI, INSPECT F 50) operated at an acceleration voltage of 20 kV was employed. The X-ray diffraction (XRD) pattern was studied using wide-angle X-ray diffractometer in the5-70o range (Bruker, D8 Advance diffractometer). Additionally, structural compositions of the FSB was extensively studied using Raman spectroscopy (Alpha 300, Witec, laser source of λ=532 nm) and Fourier transform infrared spectroscopy in Attenuated Total Reflection (A529-P/QMIRacleATR-unit (Pike), TENSOR II, Bruker) mode. The angular dependent (30o, 45o and 90o) near edge X-ray absorption fine structure (NEXAFS) spectroscopy measurements (C K-edge and F Kedge) were carried out at the beamline (BL-01) of the INDUS-2 Synchrotron Source (2.5 GeV, 130 mA) at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore, India. It was performed in ultra high vacuum (UHV) chamber with a base pressure of 10−9 Torr using spherical grating monochromator (SGM) for soft X-rays (100-1200 eV). The total electron yield was recorded by monitoring the total photocurrent from the sample, as a function of incident photon energy. 3. Results and Discussion The preparation route of FSB for electrical characterizations and nanogenerator fabrication from the bio-waste fish swim bladder (FSB) is shown in the Figure 1. The photograph of swim bladder collected from the sweet water (Catla Catla) fish (Figure. 1a) is depicted in Figure 1b. The nanoscale structural properties of the natural collagen nano-fibrils in the FSB were explored by the several characterization techniques.
First of all, the identification of the collagen nano-fibrils in the FSB was assured by the UV absorption band (Supporting Information, Figure S1) at 233 nm suggesting the presence of peptide bonds in the polypeptide chains of collagen. In addition, the absorption at 275 nm indicates the presence of few aromatic residues such as phenylalanine, tyrosine and tryptophan [22]. The collagen nanofibers morphology in the FSB derived by FE-SEM was depicted in Figure 2a. It seems that the FSB is composed of compact and highly ordered collagen nanofibers (diameter of ca. 64-65 nm). The magnified image of the selected area (left inset of Figure 2a) reveals the banded pattern with D-periodicity of 61±3 nm (right inset of Figure 2a). It reflects that the polypeptide chains of collagen are packed together in a defined and ordered manner, maintaining their native helical conformation. The cross-sectinal FE-SEM image reveals the layer structure of collagen assembly in the FSB (Supporting Information, Figure S2). The presence of protein crystal structures in the FSB is observed in the wide-angle x-ray diffractometry (WAXD) data, depicted in Figure 2b. The highly ordered collagen nanofibers are represented by the sharp peak at
. This peak also signifies the compact
intermolecular lateral packed structure within collagen fibrils with a
spacing of 1.12 nm. It
signifies the highly crystalline structure of collagen in FSB [23]. A broad reflection around arises from the amorphous components of the collagen fibrils. In addition, along the collagen triple helix structure, the axial rise distance between the amino acid residues is determined from the peak at
. The linear translation length per amino acid in a single
α-chain of the collagen is
. Furthermore, the axial translation lengths in the amino
acid residues in the N and C telopeptide are about 0.228 nm and 0.204 nm obtained from the deconvoluted peaks at
and
respectively [23].
The backbone structure and the presence of a high proportion of amino acids in collagen fibrils of the FSB are characterized by Raman spectroscopy (Figure 2c). The strongest band arises at 1677 cm-1 that corresponds to the amide I band. This band appears due to the stretching (ν) vibration of the carbonyl group (ν(C=O)) present in the peptide backbone within the Gly-X-Y tripeptide sequence. The second strongest vibrational band at 1464 cm-1 corresponds to the CH2 deformation (δ (CH2)). The presence of the amide III band is confirmed by the absorbance at 1275 cm-1 due to the in-plane deformation of N-H ( (N-H)) coupled to the C-N stretching mode (ν(C-N)) around 1246 cm-1. This band signifies the polar triple helix structure of collagen [24]. The peak at 935 cm-1 represents the C-C stretching (ν(CC)) vibration of the peptide backbone. Due to strong Raman scattering of saturated side chain rings, vibrational bands are observed at 922 and 856 cm-1 which correspond to the presence of the Pro, and the band at 883 cm-1 confirms the presence of Hyp. Thus, the Raman spectrum confirms the presence of the helical structure in collagen of the FSB with the tripeptide sequence of Gly-ProY and Gly-X-Hyp [23]. The FT-IR spectrum (Figure 2d) further confirms the amide I band at 1623 cm-1, amide II band at 1542 cm-1 (which is Raman inactive) and amide III band around 1236 cm-1 resulting from C=O stretching/ hydrogen bonding coupled with COO–, N-H-bending (δ(N-H)) coupled with C-N stretching (ν(C-N)) and N-H-bending (δ(N-H)) vibrations, respectively [25]. The absorption at 1452 cm-1 is attributed to the CH2 bending vibration [25-27]. The triple helical structure of collagens was further confirmed by the absorption ratio between the 1236 cm-1 (amide III) and 1452 cm-1 bands, which is approximately equal to 1.024 [26,27]. Generally the free N-H stretching vibration takes place in the range of 3400-3440 cm-1. In the FSB collagen the –NH group of the peptide chain is engaged with a hydrogen bond resulting in a shift towards
lower frequencies, i.e., 3281 cm-1 [26]. Other vibrational bands are observed at 2922 and 2848 cm-1 due to the CH2 asymmetrical (νas(CH2)) and symmetrical (νs(CH2)) vibrational modes, respectively, and these two combined bands indicate the presence of amide B band in the collagen fiber [25]. Thus it is evident that FSB collagen fibrils are structurally stable due to their regular chemical bonding and crystallinity. The nanoscale orientation of the –CONH hydrogen bonding motif in the collagen nano-fibrils is investigated by angular dependent NEXAFS spectroscopy which is extremely sensitive and well known powerful tool for probing the dipolar orientation [28]. The Lorentzian type sharp prominent peak at 401.5 eV in the N K-edge spectra is due to the N 1s→ (C=ONH) transition, i.e.,
transition (Figure 2e), indicating involvement of the amide
nitrogen atom into the π system of the carbamide group [29]. Also, this feature represents the presence of glycine amino acid in the peptide bond. The pre-edge features of variable intensities are observed in the N K-edge spectra due to glycine [30]. Another broad
(
) transition
arises due to the saturated nitrogen heterocycle present in proline and hydroxyproline [30]. In addition, O K-edge spectra (Figure 2f) show a sharp resonance peak at 531.6 eV due to O 1s → transition [29]. Also, the spectra manifest the broad feature of hydroxyproline due to (
) transition [30]. Most interestingly, the N K-edge and O K-edge spectra revealed
significant difference in the intensities of resonant peaks under different incidence angles (30o, 45o and 90o) of polarized X-ray photon. These changes in peak intensities are attributed to X-ray linear dichroism phenomena. This is because the cross section of the resonant photo excitation process depends on the orientation of the electric-field vector ( ⃗ ) of the incident X-ray photon with respect to the transition dipole moment (TDM) of the molecular orbital under study (a schematic is given in the inset of Figure 2f) [28]. In the case of oriented dipoles, the intensity of
the absorption resonance changes with the variation of the X-ray incident angle (θ). Both, in the N K-edge and O K-edge spectra, the dichroism of amide
are very prominent. Consequently,
markedly differences in the peak intensities are observed under 30o, 45o and 90o of incident Xray. The degree of molecular alignment in the FSB is determined from the degree of linear dichroism (P) expressed as,
where,
and
are the maximum of
(at angle, θ ~ 45o and 90o) and
resonance intensities for the field vector respectively. Here,
and
(at angle, θ ~ 30o)
are determined by considering the angle between ⃗ of the incident
X-ray photon and macromolecular axis of collagen in FSB [28]. In O K–edge spectra, we have found very strong degree of molecular alignment of maximum 13% in the FSB. The effect of the dipole alignment on the linear dichroism is summarized in the inset of Figure 2f. These results suggest a highly orientational ordering of the amide bond in the self-polarized FSB collagen. To further ensure the ferro-and piezo-electric properties of FSB, polarization (P)– electric field (E) hysteresis loop (Figure 3a) is measured, it shows remnant polarization (Pr) of 1.1 µC/cm2 and the corresponding mechanical strain (S)–electric field (E) loop (Figure 3b) is shown in Figure 3b. The converse piezoelectric effect of FSB is reflected from butterfly shaped symmetrical S–E hysteresis loop due to the polarization reversal. As, S and P are related by, S=QP2, thus from the slope of S vs. P2 plot (Figure 3c), the magnitude of longitudinal electrostrictive coefficient (Q) is found to be 0.69 m4/C2 which is more than fifteen times higher than typical inorganic piezoelectric materials, e.g., BaTiO3, PZT ceramics [31, 32]. In addition, FSB possesses a strong dielectric constant,
with low loss,
at 1 kHz (Figure
3d) compared to other available biopolymers [33]. Furthermore, it demonstrates that from 774 (at 100 Hz) to 21 (at 1 MHz) with simultaneous decrease of to 0.13 (at 1 MHz). The decrement of
as well as
decreases
from 2.4 (at 100 Hz)
with increasing frequency ensures the
ferroelectric nature of the FSB. However, the dielectric response of the FSB is almost independent of the frequency in higher frequency range (
Hz) and this is indicative for
dipolar polarization behavior. Therefore, it possesses a superior piezoelectric charge co-efficient, d33 ~ 22 pC/N (Supporting Information, Figure S3) and a converse piezoelectric coefficient, = 0.028 Vm/N. These values are comparable with scleral collagen [15]. The superior piezoelectric strength can be attributed to the layer by layer arrangement of the collagen nanofibrils and self-polarized amide bond in the FSB collagen (Figure 2e,f). Finally, we have fabricated an energy harvester termed as nanogenerator and named BPNG. The experimentally measured (Figure 4a) rectified open-circuit dc output voltages (VRoc) and short circuit currents (IRsc) generated by the BPNG under different applied stresses of human finger are shown in Figure 4b. The applied stresses ( ) were estimated depending on the generated strain (ε) within the FSB and the output voltages from the BPNG as,
|
|
where,
L is the thickness (~ 253 μm) of the FSB (Supporting Information, associate discussion S1) [7]. The BPNG exhibits
with
% s-1 and increased to
under with
with a strain rate of 1.34
(Supporting information, Figure S4 and with a strain rate of 6.72 % s−1
Video S1) when the BPNG is subjected to (Supporting information, Table S1). Interestingly, the
as well as the
show almost linear
dependencies with the applied stresses (inset of Figure 4b). Theoretically,
ε̇ , where, A~217 mm2 is the total effective
on the piezoelectric coefficients as,
area, ̇ is the applied strain rate (Supporting Information, Table S1) and Young’s modulus [7, 34]. Thus, theoretically, corresponding to
and
linearly depends
and
is the can be generated
(Supporting information, associate discussion S2
and table S2). The deviation of the experimental results from theoretical prediction is presumably
due to the charge loss in the FSB as evident in the dielectric study (Figure 3d). In order to indentify whether the signal is the true electrical output response due to piezoelectric property, widely accepted switching polarity test was performed upon reversing the output connection (Supporting information, Figure S5) [35]. In this case, the magnitude of the output voltages are same but opposite in polarity. Furthermore, under forward and reverse connection, the magnitude in peak output voltage between compress and release conditions (i.e., positive and negative peaks) are detected to be different due to the difference in straining rate when applying and releasing the stress on the BPNG [36]. Additionally, to confirm that the large output voltage is produced from the FSB, only PDMS based device (without FSB) was also fabricated under identical condition and its output voltage was carefully measured. A negligible output voltage (~ 0.01 V) is obtained (Supporting Information, Figure S6) under the mechanical stress of 1.4 MPa. These observations rule out any visible contribution of the artefacts or friction as a source of the output electrical signals from the BPNG. Basically, electricity generation in the BPNG involves piezoelectric mechanism where an electric field is generated within the FSB under mechanical deformation and the opposite charges are induced in the top and bottom electrodes. As a result, current can only flow through the external load because the FSB is a dielectric material (Figure 3d) and a positive output voltage is obtained during the stress application (Figure 4c(i) and Supporting information, inset of Figure S7). When the deformation diminishes, the built-in potential is faded out and an opposite potential is formed due to the flow of free charges in the opposite direction to balance the accumulated charges at both ends of the external circuit (Figure 4c(ii) and Supporting information, Figure S7). It has been found that the BPNG reacts very quickly with increasing stresses (Supporting information, Figure S7). To provide more insights on the working principle, the distribution of the generated charges under 1.4 MPa stress within
the FSB is shown by simulation (Figure 4d), performed via finite element method (FEM) (detail discussion is provided in supporting information, associate discussion S3). The calculated piezo– potential is consistent with our experimental observation (Figure 4b). The resulting deformation (i.e., displacement) distribution of the BPNG at the external stress amplitude of 1.4 MPa is shown in the supporting information (Figure S8). Interestingly, the maximum deformation under the compressive normal stress of 1.4 MPa is very large (~ 5 µm). In FSB, though the selfassembled peptide bonds are in compact form but still the air gap between the fibers is present which makes the FSB porous and soft. This behavior yield considerably higher displacement leading to an increased piezoelectric potential. To date, the origin of piezoelectricity in biomaterials is not completely revealed because they possess unusual behaviour and do not follow the classic models of piezoelectric theories based on idealized, crystalline structures. However, according to recent finding, the individual type I collagen fibril exhibit shear piezoelectricity due to the presence of N and C terminal telopeptides and C6 symmetry [19]. In contrast, a collection of ordered collagen fibril present in FSB, exhibits a complete different behaviour as we have noticed. Previously, this kind of difference was also observed in M13 bacteriophage [20]. The possible explanation for such kind of behaviour, as suggested recently [37], is that the application of compressive stress on the compact and ordered collagen causes neighbouring α helices on the collagen surface to rub against each other, possessing intrapolypeptide –CONH hydrogen bonding motif. This results in the deformation of the triple helical structure and new electric dipole moments are developed. As the FSB possess layer by layer arrangement of the collagen nano-fibrils (Supporting Information, Figure S2) the generation of electric dipole moments due to their internal rubbing is large under applied stress [37]. Another suggested possible explanation is that [37], as collagen possesses C6 symmetry, the compressive
deformation could break this symmetry and subsequently produce new charges on the top and bottom surfaces of the FSB. In this case, these effects are amplified by the presence of interpolypeptide –CONH hydrogen bonding motif being formed between the polypeptide chains of neighbouring α helices in the highly oriented collagen crystal (Figure 4e) [12,13]. More substantially, the enhancement of the piezoelectric response in the FSB associated to the cooperative electromechanical mutual interaction among the self-aligned adjacent fibers during applied pressure compared to single fiber [19, 38]. Thus, it is quite expected and desirable that the FSB shows longitudinal piezoelectric effect. To further investigate the ultra sensitivity of the BPNG, it was arranged as a vibration sensor by mounting it in cantilever arrangement (left upper inset of Figure 5a). It allows the BPNG to vibrate freely under each finger striking from 3 cm of height. Therefore, each gentle finger striking generates open circuit voltage of 3 V (Figure 5a). The damping behavior in the output performance again signifies the piezoelectric characteristics of the BPNG [39]. Fitted amplitude of the single output using exponential function, results the damping factor,
(where t is time)
of 15.8 (right upper inset of Figure 5a) which is comparable with
the ZnO based piezoelectric nanogenerator [39]. The BPNG also responses well under the machine vibration (i.e., imparted periodically with the cylindrical stepper motor probe of portable sewing machine as demonstrated previously) [8] and generates Voc ~ 3.6 V with proper reversibility (Figure 5b) under
~ 0.5 MPa. The fatigue test of the BPNG has been performed
by recording the output voltage as a function of time over extended cycling times (1800 cycles) under 0.75 MPa compressive stress by human finger tapping, indicates the long term stability of BPNG (Figure 5c). To investigate the potential applicability of the BPNG commercially available capacitor of 10 μF capacitance was connected to the BPNG via full wave bride rectified
circuit and charged up under repeated applied stress (Figure 5d). The low time constant value (τ ~ 169 s) ensures the rapid energy supply ability of the BPNG. Thus, we have successfully stored 28.9 μJ energy delivered by the BPNG across a 10 μF capacitor. In case of normal animals, the minimum external electric energy required for triggering the action potential of the artificially contracted heart is 1.1 µJ [3, 40]. Thus, quick and sufficient charge generating capability enables the BPNG to be applicable for biomedical sensor fabrication and interfacing with human body parts. Furthermore, the bridge rectified output voltage and current are measured as a function of the external load resistance ranging from 100 kΩ to 40 MΩ (Figure 5e and Supporting Information, Figure S9). The instantaneous voltage drop across resistances supplied by the BPNG gradually increases with the increment of the resistance, and saturates at an extremely high resistance (~ 40 MΩ) corresponding to the open-circuit voltage. In contrast, short-circuit current outputs are gradually decreased from the saturated short–circuit current upon increasing the load resistance (Figure 5e). The BPNG is able to deliver a maximal instantaneous power density (calculated by across load resistance
, where, A is the effective contact area,
is the voltage drop
respectively) of 4.15 μW/cm2 across 9 MΩ load resistance (Figure 5f).
At this condition, piezoelectric energy conversion efficiency (
) of BPNG is 0.3 %
(Supporting information, associate discussion S4). Thus, the BPNG drive several colored LEDs such as blue, green, red and also white separately where external batteries are not used (Supporting information, Video S2). Particularly, the BPNG lit up a series of 55 blue LEDs (inset of Figure 5f and) proving the efficiency and utility of BPNG in portable electronic system. It is evident from the current (I)–voltage (V) characteristic of a single blue LED that the output current (IRsc) of 51 nA is sufficient enough to turn on the blue LED. As 55 LEDs are in series connection, so all LEDs experience same amount of current and glow simultaneously. Since, the
resistance of the LED is very low which is far below than the load resistance where the rapid change of IRsc has been observed (Figure 5e). So, the current across 55 LEDs is almost the same as IRsc. Another important point is that the maximum power output of BPNG is observed across 9 MΩ load resistance and the resistance of a single blue LED is far below the maximum power point [41]. So, BPNG is enabling to flash the 55 LEDs connected in series. Basically, BPNG can be considered as a charge (q) source in parallel with an internal capacitor (Ci) and a resistor (Ri) (inset of Figure 5d). Therefore, BPNG acts as a good power source under mechanical impact and the outputs fit well with linear circuit theory which evaluates the value of internal resistance, Ri ~ 4.55 MΩ (Supporting Information, Figure S10 and associated discussion S6). According to the RC circuit model, the evaluated internal capacitance of the BPNG is 27 μF (Supporting Information, associate discussion S7). Thus, low internal resistance with higher capacitance makes the BPNG more suitable power source for its potential application in flexible portable electronic devices [42]. More importantly, the output voltage of BPNG is very much stable irrespective of environmental variation as we have tested over 18000 cycles up to 90 days (Figure 6a). In addition, the BPNG was also capable to sense and harvest mechanical energy arises during normal walking and football playing motions (Figure 6b). Thus, biomechanical assessments for musculoskeletal injuries and anthropometry can be performed in self-powered mode using BPNG depending on age, height and body mass of sports person and workers [43]. In overall, our BPNG is very much comparable and even superior in some cases with the previously reported bio–piezoelectric materials (Supporting Information, Table S3). 4. Conclusion In summary, we developed fish collagen, a natural resource based robust nanogenerator, i.e., biopiezoelectric nanogenerator (BPNG) posses several merits. It is capable of producing an open-
circuit voltage of 10 V and short–circuit current of 51 nA under a compressive normal stress of 1.4 MPa with theoretical validation. It can also generates outstanding power density of 4.15 μW/cm2 with its inherent high piezoelectric energy conversion efficiency of ~ 0.3 %. With these merits, the BPNG potentially offers a broad range of applications ranging from biomedicine to electronic skin sensors in robotics and for the development of self-powered portable electronic systems. Due to the biocompatibility of the collagen fibril, the potential use of the BPNG as biomedical sensors is quite expected where the implantation of the BPNG in a living body is possible to harvest energy from different bio signals such as respiration, heartbeat, blood circulation etc. Associated Content Supporting Information Additional information on, detail discussions on material characterizations and nanogenerator fabrication process, UV-vis absorption spectra, cross-sectional image, measured d33 value, and dielectric spectra of FSB are given. In addition, theoretical calculation of applied stress, current measurement, fatigue test, theoretical simulation, calculated energy conversion efficiency, internal resistance and several vibrational responses from the BPNG are also elaborately given.
Author Information Funding Sources This work was financially supported by a grant from the Science and Engineering Research Board (SERB/1759/2014−15), Government of India.
The authors declare no competing financial interest.
Acknowledgements This work was financially supported by a grant from the Science and Engineering Research Board (SERB/1759/2014-15), Government of India. Authors are also grateful to DST, Govt. of India for their helping hand to develop the instrumental facilities under FIST-II programme and for awarding INSPIRE fellowship (IF130865) to Mr. Sujoy Kumar Ghosh. We acknowledge to Mr. Samiran Garain for his skilful FE-SEM operation. Authors also thank for the support from Dr. Karsten Henkel (BTU Cottbus-Senftenberg, Angewandte Physik-Sensorik, K.-WachsmannAllee 17, 03046 Cottbus, Germany) and Mr. S.P. Mandal for their valuable suggestions while preparing manuscript. We are thankful to Dr. D. K. Shukla and Dr. D. M. Phase for availability and measurement of NEXAFS. We also acknowledge help from Mr. Rakesh Kumar Sah during NEXAFS measurements. We also greatly acknowledge to Dr. Shrabanee Sen (Scientist, Sensor and Actuator Division, Central Glass and Ceramic Research Institute (CSIR)) for helping d33 measurement.
Conflict of interest The authors declare no competing financial interest.
References [1] Z. L. Wang, J. Song, Science 312 (2006) 242–246. [2] Z. Li, G. Zhu, R. Yang, A. C. Wang, Z. L. Wang, Adv. Mater. 22 (2010) 2534–2537.
[3] G. T. Hwang, H. Park, J. H. Lee, S. Oh, K. I. Park, M. Byun, H. Park, G. Ahn, C. K. Jeong, K. No, H. Kwon, S. G. Lee, B. Joung, K. J. Lee, Adv. Mater. 26 (2014) 4880–4887. [4] M. M. Alam, S. K. Ghosh, A. Sultana, D. Mandal, Nanotechnology 26 (2015) 165403. [5] J. Yan, Y. G. Jeong, ACS Appl. Mater. Interfaces 8 (2016) 15700−15709. [6] F. R. Fan, W. Tang, Z. L. Wang, Adv. Mater. 28 (2016) 4283–4305. [7] S. K. Ghosh, T. K. Sinha, B. Mahanty, D. Mandal, Energy Technol. 3 (2015) 1190–1197. [8] A. Tamang, S. K. Ghosh, S. Garain, M. M. Alam, J. Haeberle, K. Henkel, D. Schmeisser, D. Mandal, ACS Appl. Mater. Interfaces 7 (2015) 16143−16147. [9] C. Ribeiro, V. Sencadas, D. M. Correia, S. Lanceros-Mendez, Colloids and Surfaces B: Biointerfaces 136 (2015) 46–55. [10] Y. Kanzaki, F. Terasaki, M. Okabe, S. Fujita, T. Katashima, K. Otsuka, N. Ishizaka, Circulation 122 (2010) 1973–1974. [11] K. A. Piez, J. Gross, J. Biol. Chem. 235 (1960) 995–998. [12] A. Rich, F. H. C. Crick, J. Mol. Biol. 3 (1961) 483–506. [13] R. D. B. Fraser, T. P. Macrae, E. Suzuki, J. Mol. Biol. 129 (1979) 463–481. [14] H. Athenstaedt, Nature 228 (1970) 830–834. [15] S. Ghosh, B. Z. Mei, V. Lubkin, J. I. Scheinbeim, B. A. Newman, P. Kramer, G. Bennett, N. Feit, J. Biomed. Mater. Res 39 (1998) 453–457. [16] S. Mascarenhas, Electrets: chap.6. Bioelectrets: Electrets in Biomaterials and Biopolymers, Springer-Verlag, Berlin, 1987. [17] E. Fukada, Electr. Insul. IEEE Trans. 27 (1992) 813–819. [18] E. Fukada, I. Yasuda, Jpn. J. Appl. Phys. 3 (1964) 117–121.
[19] M. M. Jolandan, M. F. Yu, Nanotechnology 20 (2009) 085706. [20] B. Y. Lee, J. Zhang, C. Zueger, W. J. Chung, S. Y. Yoo, E. Wang, J. Meyer, R. Ramesh, S.W. Lee, Nat. Nanotech. 7 (2012) 351–356. [21] S. J. Kim, D. B. Jeon, J. H. Park, M. K. Ryu, J. H. Yang, C. S. Hwang, G. H. Kim, S. M. Yoon, ACS Appl. Mater. Interfaces 7 (2015) 4869–4874. [22] J. W. Donovan, in: Physical Principal and Techniques of Protein Chemistry (Part A), Academic Press, New York, 1969, pp. 101-102. [23] B. Wu, C. Mu, G. Zhang, W. Lin, Langmuir 25 (2009) 11905–11910. [24] B. G. Frushour, J. L. Koenig, Biopolymers 14 (1975) 379–391. [25] J. H. Muyongaa, C. G. B. Cole, K. G. Duodu, Food Chem. 85 (2004) 81–89. [26] L. Wang, Q. Liang, T. Chen, Z. Wang, J. Xu, H. Ma, Food Hydrocolloids 38 (2014) 104– 109. [27] O. Kaewdang, S. Benjakul, T. Kaewmanee, H. Kishimura, Food Chem. 155 (2014) 264– 270. [28] J. St ̈ hr, NEXAFS Spectroscopy, Springer–Verlag, Berlin, 1992. [29] M. L. Gordon, G. Cooper, C. Morin, T. Araki, C. C. Turci, K. Kaznatcheev, A. P. Hitchcock, J. Phys. Chem. A 107 (2003) 6144–6159. [30] Y. Zubavichus, A. Shaporenko, M. Grunze, M. Zharnikov, J. Phys. Chem. A 109 (2005) 6998–7000. [31] B. G. Baraskar, S. G. Kakade, A. R. James, R. C. Kambale, and Y. D. Kolekar, AIP Conf. Proc. 1731, 140066 (2016). [32] T. Furukawa, and N. Seo, Jpn. J. Appl. Phys. 29, 675 (1990).
[33] H. S. Nalwa, Handbook of Low and High Dielectric Constant Materials and Their Applications, Academic Press, London, 1999. [34] M. A. Nawaz, Degree Thesis on Material and Acoustic Properties of Swim bladders of Tilapia and Channel Catfish. Diss. Virginia Commonwealth University Richmond, Virginia, 2005. [35] R. Yang, Y. Qin, C. Li, L. Dai, Z. L. Wang, Appl. Phys. Lett. 94 (2009) 022905. [36] J. H. Jung, M. Lee, J. Hong, Y. Ding, C. Y. Chen, L. J. Chou, Z. L. Wang, ACS Nano 5 (2011) 10041–10046. [37] S. M. Yu, Nat. Nanotech. 7 (2012) 343–344. [38] L. Persano, C. Dagdeviren, C. Maruccio, L. D. Lorenzis, D. Pisignano, Adv. Mater. 26 (2014) 7574–7580. [39] A. Yu, P. Jiang, Z. L. Wang, Nano Energy 1 (2012) 418–423. [40] T. E. Starzl, R. A. Gaertner, R. C. Webb Jr., Circulation 11 (1955) 952–962. [41] S. Wang, L. Lin, Z. L. Wang, Nano Lett. 12 (2012) 6339–6346. [42] S. Niu, S. Wang, L. Lin, Y. Liu, Y. S. Zhou, Y. Hu, Z. L. Wang, Energy Environ. Sci. 6 (2013) 3576–3583. [43] P. Madeleine, A. Samani, M. Zee, U. Kersting, Biomechanical Assessments in Sports and Ergonomics, Theoretical Biomechanics, Dr Vaclav Klika (Ed.), ISBN: 978-953-307-851-9, InTech, 2011.
(a)
(b) (c)
Fig 1. Collection and preparation of the FSB for electrical characterization (a) The photograph of the sweet water (Catla Catla) fish from where (b) the swim bladder was collected to be used in this study. (c) The flexibility of the fish swim bladder (FSB) with sputtered Au electrodes was demonstrated by human finger.
(b)
(c)
(e)
(d)
(f)
Fig 2. The structural characterization of the fish swim bladder (FSB). (a) FE-SEM image with left inset representing a single collagen fiber to calculate the D-periodicity indicated by the histogram profile in the right inset, (b) WAXD pattern in the range of 2θ ~ 5o–70o, (c) Raman spectrum in the region of 1800–800 cm-1, (d) ATR-FTIR spectrum in 4000–1000 cm-1 region. Angular dependent NEXAFS spectra (normalized) of (e) N K-edge and (f) O K-edge spectra. Inset shows the incident beam geometry with respect to the FSB and degree of linear dichroism (%) as a function of incident beam direction, θ.
(a)
(b)
(c)
(d)
Fig 3. (a) Standard polarization (P)–electric field (E) hysteresis loop and (b) the corresponding strain (S)–electric field (E) hysteresis loop of FSB under the electric field of
with
frequency of 1 kHz. (c) The S versus P2 plot. (d) Frequency dependent dielectric spectra in the frequency range of 100 Hz– 1MHz.
6
VRoc (V)
4
10
2 0
0.3 0.6 0.9 1.2 1.5
50 40 30 20 10 0
IRsc (nA)
VRoc (V)
15
(b)108
1.4 MPa
Stress (MPa)
0.75 MPa
5 0.28 MPa
0
0
(c) (i)
(ii)
(e)
2
(d)
4
Time (s)
Stress
6
Fig 4. Characterizations of the BPNG. (a) Operation demonstration of the BPNG for mechanical energy harvesting by finger impact. (b) The rectified output voltages from the BPNG by different stresses with stress dependent output voltages and currents in inset. (c) Schematic illustration of the mechanism involved in the energy harvesting performance of the BPNG under stress impact and release motion. (d) The simulated charge distribution FEM model inside the BPNG under 1.4 MPa stress. (e) The schematic illustration of intra- and inter-peptide chains of collagen with Gly-Pro-Hyp amino acids motif sequence to understand the origin of polarization in the FSB.
(a)
(b)
𝛽
𝑒
𝛽𝑡
(c)
(d)
(e)
(f)
Fig 5. Several applications of the BPNG (a) The output response of the BPNG as a vibration sensor after several excitations. Left upper inset shows the schematic of the experimental set up. Right upper inset shows the close view of the output response during one excitation with its fitting amplitude by exponential function. (b) The machine vibration response of the BPNG with proper dipole reversibility (right upper inset) using a simple portable swing machine (left upper inset). (c) The stability test of the BPNG under 0.75 MPa stress by human finger tapping (The horizontal red dotted lines serve as guides to the eye). (d) Fast capacitor charging performance of the BPNG is demonstrated. The inset shows the schematic circuit diagram used to charge 10 µF capacitor (e) Dependences of output voltage and current on variable external load resistance. (f) Instantaneous output power density of the BPNG as a function of variable load resistance. The inset shows an array of 55 blue LEDs in series displaying ‘ONPDL’, an array of 22 serial connected green LEDs representing ‘JU’ as well as one red and one white LED which are instantly turned on by the electricity generated from the BPNG. The real-time I−V characteristic of a single blue LED from its OFF state to ON state is shown in the inset.
(a)
(b)
Fig 6. (a) The mechanical durability test of BPNG over 18000 cycles up to 90 days. (b) The pulse output voltages from the BPNG when it was impacted by different parts of foot during normal walking, pushing and juggling by football. Author Biography
Mr. Sujoy Kumar Ghosh is pursuing PhD from Department of Physics, Jadavpur University, India. He received his M.Sc and B.Sc. degree in physics from Jadavpur University in 2012 and 2010 respectively. His research interest includes polymer based piezo-, pyro- and ferro-electric energy harvester and synthesis piezoelectric nanomaterial.
Dr. Dipankar Mandal is an Assistant Professor in the Department of Physics, Jadavpur University, India. He completed his M.Sc. in 2002 from Jadavpur University and M.Tech. in
2004 from Indian Institute of Technology, Kharagpur. He received his PhD in 2008 from BTU Cottbus, Germany. His research interest focused on advanced functional materials, polymer electronics, piezoelectric and ferroelectric polymers, sol-gel chemistry, semi-conducting materials, biosignal monitoring using various types of nano invasive biosensors, polymeric nanogenerator, metal nanoparticles, rare-earth doped glass.
Video S1: The bridge rectified peak output current,
measurement of BPNG by periodical
human finger impact from different heights. Video S2: A series of 55 commercial blue LEDs directly driven by BPNG. Furthermore, several colour LEDs such as 22 green, one red and one white LED are directly operated by BPNG.
Graphical Abstract
Highlights
The direct fabrication of an efficient bio-piezoelectric nanogenerator (BPNG) from fish (Catla Catla) swim bladder (FSB).
The self-alignment of the molecular dipoles in the FSB collagen is confirmed by the angular dependent Near edge X-ray Absorption Spectroscopy (NEXAFS). The large piezoelectric charge coefficient ( ~ 22 pC/N) enables the BPNG to generate the open-circuit voltage of 10 V and short-circuit current of 51 nA under compressive normal stress (~ 1.4 MPa) by human finger. The high power throughput of 4.15 μW/cm2 with inherent piezoelectric energy conversion efficiency (~ 0.3%). Furthermore, the BPNG instantly turns on more than 50 commercial blue LEDs which are unable to drive by a battery of 8.66 V. For real time demonstration we have also provided the associated video files mentioned in the supporting file.
Graphical Abstract
Efficient Natural Piezoelectric Nanogenerator: Electricity Generation from Fish Swim Bladder Sujoy Kumar Ghosh and Dipankar Mandal*
Organic Nano-Piezoelectric Device Laboratory (ONPDL), Department of Physics Jadavpur University, Kolkata 700032, India *
Corresponding author. Tel.: +91 33 2414 6666x2880; fax: +91 33 2413 8917
E-mail address: [email protected] TOC Graphic
Green and clean energy harvesting via fabrication of a bio-degradable and bio-compatible piezoelectric nanogenerator i.e., bio-piezoelectric nanogenerator (BPNG) from waste fish byproducts is spot lighted through one step process.
www.elsevier.com/locate/nanoenergy
PII: DOI: Reference:
S2211-2855(16)30319-6 http://dx.doi.org/10.1016/j.nanoen.2016.08.030 NANOEN1443
To appear in: Nano Energy Received date: 6 June 2016 Revised date: 2 August 2016 Accepted date: 10 August 2016 Cite this article as: Sujoy Kumar Ghosh and Dipankar Mandal, Efficient Natural Piezoelectric Nanogenerator: Electricity Generation from Fish Swim Bladder, Nano Energy, http://dx.doi.org/10.1016/j.nanoen.2016.08.030 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Efficient Natural Piezoelectric Nanogenerator: Electricity Generation from Fish Swim Bladder
Sujoy Kumar Ghosh, Dipankar Mandal*
Organic Nano-Piezoelectric Device Laboratory, Department of Physics. Jadavpur University, Kolkata 700032, India *
Corresponding author. Tel.: +91 33 2414 6666x2880; fax: +91 33 2413 8917.
[email protected]
Abstract An efficient bio-piezoelectric nanogenerator (BPNG) is fabricated from the fish swim bladder (FSB), composed of well-aligned natural collagen nano–fibrils. The self-alignment of highly ordered structure in the FSB collagen has been confirmed by angular dependent near edge X-ray absorption fine structure (NEXAFS) spectroscopy. Compressive normal stress by human finger can able to drive the BPNG that generates an open-circuit voltage of 10 V and short-circuit current of 51 nA. The generated electricity from the FSB instantly turns on more than 50 commercial blue light emitting diodes (LEDs), indicates to use as a sustainable power source in portable electronic devices where the bulky battery counterpart can be avoided. The instantaneous piezoelectric power generation (~ 4.15 μW/cm2) and substantial energy conversion efficiency (~ 0.3 %) of BPNG promises an emerging application, particularly to built self-
powered biomedical sensors because collagen itself one of the most abundant protein available in human body.
Graphical Abstract Green and clean energy harvesting via fabrication of a bio-degradable and bio-compatible piezoelectric nanogenerator i.e., bio-piezoelectric nanogenerator (BPNG) from waste fish byproducts is spot lighted through one step process.
Keywords fish swim bladder, natural piezoelectric material, bio-piezoelectric nanogenerator, collagen nano fibrils, mechanical energy harvester, self-powered biomedical sensor
1. Introduction A self-powered system allows the in-situ, real time biomedical health monitoring. Among currently available technologies, piezoelectric materials based self-powered nanogenerators (NGs) have attracted rapid growing interest as a new kind of energy source due to the applicability as biomedical devices and suitability in flexible portable electronics [1-8]. Several efforts have been made to fabricate NGs based on several piezoelectric materials such as ZnO [2], PMN-PT [3], ZnSnO3 [4], BaTiO3 [5], PZT [6], and synthetic polymers (e.g., PVDF and its copolymers) [7,8]. To adapt a self-powered system as an implantable biomedical device, such as artificial cardiac pacemaker, the material used for the energy harvesting system is the most
important issue, because under in vivo monitoring condition even a very low level of toxicity originating from the self-powered system can cause heart failure and harm the patient. Thus, a biomaterial based self-powered system is the alternative to overcome this long standing challenge. The most easily available biomaterial possessing intrinsic piezoelectricity is the collagen fibril, which is also bio-degradable, bio-compatible and abundantly present in animal tissues such as skin, tendon, cartilage, bone and even in human heart itself [9,10]. Animal skins dominantly contain type I collagen. It is composed of three polypeptide chains (α-chain), two identical α1(I) chains and a different α2(I) chain. Each of them consists of repeated triplet amino acid motif sequences of Gly (Glycine)-X-Y, in which X and Y are frequently proline (Pro) and hydroxyproline (Hyp), respectively [11]. The three α-chains twist together into a unique triplehelical structure. The collagen monomers comprise of such a long helical region in length and short non-helical N and C-terminal telopeptides. The quarter staggered arrangement of the collagen molecules contributes to collagen fibrils with a characteristic axial periodic structure, and the fibrils further assemble into a collagen fiber [12,13]. The hydrogen bond formation between the polypeptide chains plays the essential role for the piezoelectricity. The intrinsic presence of the polar uniaxial orientation of molecular dipoles causes polarization and the piezoelectricity which makes the collagen to become a natural electret or bioelectret material as well [14-19]. To date, very few attempts have been undertaken to explore the potential applications of the naturally occurring electret materials [18-21], and this is the first attempt where the applicability of bio-piezoelectric nanogenerator (BPNG), fabricated directly from fish swim bladder (FSB) is demonstrated. In this approach, we directly use fish (Catla Catla, a fresh sweet water fish) swim bladder (mainly a waste product in fish processing) composed of naturally well aligned collagen nano-
fibrils to fabricate a BPNG. As a direct proof of evidence, dipolar orientation persisting in FSB collagen is exclusively confirmed by angular dependent NEXAFS study. The BPNG exhibits an open-circuit voltage (VRoc) of 10 V and a short-circuit current (IRsc) of 51 nA under repeated periodic compressive normal stress (~ 1.4 MPa) imparted by human finger. Our BPNG is able to deliver an output power density of 4.15 μW/cm2 with superior piezoelectric energy conversion efficiency (~ 0.3 %) which is demonstrated to power up several colour light emitting diodes (LEDs) such as 50 blue, 22 green as well as red and white LEDs that pave the way for potential application in portable electronics and implantable biomedical sensors. 2. Experimental 2.1. Collection of the fish swim bladder The fish swim bladder used in the experiments was collected from nearby Jadavpur University market. The FSB is basically thrown away during food processing. It was cleaned by de-ionized water and subsequently dried in room temperature. Then it was cut into rectangular shape (17.5 mm × 13.5 mm) for entire experiments. It should be noted that no live animal experiments have been performed. The average thickness of the FSB was 253±10 µm measured by digital slide caliper (CD-6''VC, Mitutoyo) and cross checked from cross-sectional FE-SEM images. 2.2. Electrical measurements At first, the gold (Au) electrode with 90 nm of thickness was deposited on both sides of FSB at room temperature with specific operating conditions such as, deposition rate of 0.13 nm/s, 0.1 mTorr of working pressure, 2.5 kV of applying voltage, 20 mA of current and the target to specimen distance of 50 mm. The temperature arises during Au sputtering is of less than 1 oC which does not affect the collagen crystals of FSB. After Au sputtering, the FSB was still
flexible which is demonstrated in Figure 1c. The dielectric properties of the FSB with Au sputtered electrodes were measured in the frequency range from 100 Hz to 1 MHz at room temperature using a precision impedance analyzer (Wayne Kerr, 6500B). The d 33 value of the same FSB was measured by d33 meter (Piezotest, PM300) in HI/d33 mode (where capacitance, C measurement of the material is inactive) under the constant applied force of 0.4 N and frequency at 110 Hz after calibrating the instrument with a piezoMeter reference sample whose d33 value is 349 pC/N. 2.3. Nanogenerator Fabrication To fabricate the robust nanogenerator (BPNG), the gold sputtered FSB (with effective area, A~ 217 mm2 and thickness, t~ 253 μm) was attached with fine copper wires by means of silver paste. Finally, the FSB was encapsulated with PDMS (Sylgard, 184 SILICONE ELASTOMER) layer, prepared by 10:1 curing agent and cured in an oven at 60oC for 30 m. The final cured thickness of PDMS layer is about 1 mm i.e., total thickness of the BPNG is 1 mm including FSB. Thus, the thickness of the PDMS layer on either side of the FSB is 374 µm. The dimension of the BPNG was kept
.
2.4. BPNG performance characterization The output performance of the BPNG has been investigated by periodical human finger imparting vertically to the electrodes (Figure 4a). To demonstrate the stress ( ) dependent VRoc and IRsc, the human finger was impacted from different heights (Table S1) to generate several stresses, maintaining an average frequency of ~ 6 Hz. The output voltage and current from the BPNG under several stresses were recorded with a digital storage oscilloscope (Agilent DSO3102A) and digital pico-ammeter (DPA 111) respectively.
2.5. Materials characterizations The UV-vis absorption spectrum was recorded by spectrophotometer (3110PC, Shimadzu). To investigate the detailed surface morphology, Field Emission Scanning Electron Microscopy (FEI, INSPECT F 50) operated at an acceleration voltage of 20 kV was employed. The X-ray diffraction (XRD) pattern was studied using wide-angle X-ray diffractometer in the5-70o range (Bruker, D8 Advance diffractometer). Additionally, structural compositions of the FSB was extensively studied using Raman spectroscopy (Alpha 300, Witec, laser source of λ=532 nm) and Fourier transform infrared spectroscopy in Attenuated Total Reflection (A529-P/QMIRacleATR-unit (Pike), TENSOR II, Bruker) mode. The angular dependent (30o, 45o and 90o) near edge X-ray absorption fine structure (NEXAFS) spectroscopy measurements (C K-edge and F Kedge) were carried out at the beamline (BL-01) of the INDUS-2 Synchrotron Source (2.5 GeV, 130 mA) at Raja Ramanna Centre for Advanced Technology (RRCAT), Indore, India. It was performed in ultra high vacuum (UHV) chamber with a base pressure of 10−9 Torr using spherical grating monochromator (SGM) for soft X-rays (100-1200 eV). The total electron yield was recorded by monitoring the total photocurrent from the sample, as a function of incident photon energy. 3. Results and Discussion The preparation route of FSB for electrical characterizations and nanogenerator fabrication from the bio-waste fish swim bladder (FSB) is shown in the Figure 1. The photograph of swim bladder collected from the sweet water (Catla Catla) fish (Figure. 1a) is depicted in Figure 1b. The nanoscale structural properties of the natural collagen nano-fibrils in the FSB were explored by the several characterization techniques.
First of all, the identification of the collagen nano-fibrils in the FSB was assured by the UV absorption band (Supporting Information, Figure S1) at 233 nm suggesting the presence of peptide bonds in the polypeptide chains of collagen. In addition, the absorption at 275 nm indicates the presence of few aromatic residues such as phenylalanine, tyrosine and tryptophan [22]. The collagen nanofibers morphology in the FSB derived by FE-SEM was depicted in Figure 2a. It seems that the FSB is composed of compact and highly ordered collagen nanofibers (diameter of ca. 64-65 nm). The magnified image of the selected area (left inset of Figure 2a) reveals the banded pattern with D-periodicity of 61±3 nm (right inset of Figure 2a). It reflects that the polypeptide chains of collagen are packed together in a defined and ordered manner, maintaining their native helical conformation. The cross-sectinal FE-SEM image reveals the layer structure of collagen assembly in the FSB (Supporting Information, Figure S2). The presence of protein crystal structures in the FSB is observed in the wide-angle x-ray diffractometry (WAXD) data, depicted in Figure 2b. The highly ordered collagen nanofibers are represented by the sharp peak at
. This peak also signifies the compact
intermolecular lateral packed structure within collagen fibrils with a
spacing of 1.12 nm. It
signifies the highly crystalline structure of collagen in FSB [23]. A broad reflection around arises from the amorphous components of the collagen fibrils. In addition, along the collagen triple helix structure, the axial rise distance between the amino acid residues is determined from the peak at
. The linear translation length per amino acid in a single
α-chain of the collagen is
. Furthermore, the axial translation lengths in the amino
acid residues in the N and C telopeptide are about 0.228 nm and 0.204 nm obtained from the deconvoluted peaks at
and
respectively [23].
The backbone structure and the presence of a high proportion of amino acids in collagen fibrils of the FSB are characterized by Raman spectroscopy (Figure 2c). The strongest band arises at 1677 cm-1 that corresponds to the amide I band. This band appears due to the stretching (ν) vibration of the carbonyl group (ν(C=O)) present in the peptide backbone within the Gly-X-Y tripeptide sequence. The second strongest vibrational band at 1464 cm-1 corresponds to the CH2 deformation (δ (CH2)). The presence of the amide III band is confirmed by the absorbance at 1275 cm-1 due to the in-plane deformation of N-H ( (N-H)) coupled to the C-N stretching mode (ν(C-N)) around 1246 cm-1. This band signifies the polar triple helix structure of collagen [24]. The peak at 935 cm-1 represents the C-C stretching (ν(CC)) vibration of the peptide backbone. Due to strong Raman scattering of saturated side chain rings, vibrational bands are observed at 922 and 856 cm-1 which correspond to the presence of the Pro, and the band at 883 cm-1 confirms the presence of Hyp. Thus, the Raman spectrum confirms the presence of the helical structure in collagen of the FSB with the tripeptide sequence of Gly-ProY and Gly-X-Hyp [23]. The FT-IR spectrum (Figure 2d) further confirms the amide I band at 1623 cm-1, amide II band at 1542 cm-1 (which is Raman inactive) and amide III band around 1236 cm-1 resulting from C=O stretching/ hydrogen bonding coupled with COO–, N-H-bending (δ(N-H)) coupled with C-N stretching (ν(C-N)) and N-H-bending (δ(N-H)) vibrations, respectively [25]. The absorption at 1452 cm-1 is attributed to the CH2 bending vibration [25-27]. The triple helical structure of collagens was further confirmed by the absorption ratio between the 1236 cm-1 (amide III) and 1452 cm-1 bands, which is approximately equal to 1.024 [26,27]. Generally the free N-H stretching vibration takes place in the range of 3400-3440 cm-1. In the FSB collagen the –NH group of the peptide chain is engaged with a hydrogen bond resulting in a shift towards
lower frequencies, i.e., 3281 cm-1 [26]. Other vibrational bands are observed at 2922 and 2848 cm-1 due to the CH2 asymmetrical (νas(CH2)) and symmetrical (νs(CH2)) vibrational modes, respectively, and these two combined bands indicate the presence of amide B band in the collagen fiber [25]. Thus it is evident that FSB collagen fibrils are structurally stable due to their regular chemical bonding and crystallinity. The nanoscale orientation of the –CONH hydrogen bonding motif in the collagen nano-fibrils is investigated by angular dependent NEXAFS spectroscopy which is extremely sensitive and well known powerful tool for probing the dipolar orientation [28]. The Lorentzian type sharp prominent peak at 401.5 eV in the N K-edge spectra is due to the N 1s→ (C=ONH) transition, i.e.,
transition (Figure 2e), indicating involvement of the amide
nitrogen atom into the π system of the carbamide group [29]. Also, this feature represents the presence of glycine amino acid in the peptide bond. The pre-edge features of variable intensities are observed in the N K-edge spectra due to glycine [30]. Another broad
(
) transition
arises due to the saturated nitrogen heterocycle present in proline and hydroxyproline [30]. In addition, O K-edge spectra (Figure 2f) show a sharp resonance peak at 531.6 eV due to O 1s → transition [29]. Also, the spectra manifest the broad feature of hydroxyproline due to (
) transition [30]. Most interestingly, the N K-edge and O K-edge spectra revealed
significant difference in the intensities of resonant peaks under different incidence angles (30o, 45o and 90o) of polarized X-ray photon. These changes in peak intensities are attributed to X-ray linear dichroism phenomena. This is because the cross section of the resonant photo excitation process depends on the orientation of the electric-field vector ( ⃗ ) of the incident X-ray photon with respect to the transition dipole moment (TDM) of the molecular orbital under study (a schematic is given in the inset of Figure 2f) [28]. In the case of oriented dipoles, the intensity of
the absorption resonance changes with the variation of the X-ray incident angle (θ). Both, in the N K-edge and O K-edge spectra, the dichroism of amide
are very prominent. Consequently,
markedly differences in the peak intensities are observed under 30o, 45o and 90o of incident Xray. The degree of molecular alignment in the FSB is determined from the degree of linear dichroism (P) expressed as,
where,
and
are the maximum of
(at angle, θ ~ 45o and 90o) and
resonance intensities for the field vector respectively. Here,
and
(at angle, θ ~ 30o)
are determined by considering the angle between ⃗ of the incident
X-ray photon and macromolecular axis of collagen in FSB [28]. In O K–edge spectra, we have found very strong degree of molecular alignment of maximum 13% in the FSB. The effect of the dipole alignment on the linear dichroism is summarized in the inset of Figure 2f. These results suggest a highly orientational ordering of the amide bond in the self-polarized FSB collagen. To further ensure the ferro-and piezo-electric properties of FSB, polarization (P)– electric field (E) hysteresis loop (Figure 3a) is measured, it shows remnant polarization (Pr) of 1.1 µC/cm2 and the corresponding mechanical strain (S)–electric field (E) loop (Figure 3b) is shown in Figure 3b. The converse piezoelectric effect of FSB is reflected from butterfly shaped symmetrical S–E hysteresis loop due to the polarization reversal. As, S and P are related by, S=QP2, thus from the slope of S vs. P2 plot (Figure 3c), the magnitude of longitudinal electrostrictive coefficient (Q) is found to be 0.69 m4/C2 which is more than fifteen times higher than typical inorganic piezoelectric materials, e.g., BaTiO3, PZT ceramics [31, 32]. In addition, FSB possesses a strong dielectric constant,
with low loss,
at 1 kHz (Figure
3d) compared to other available biopolymers [33]. Furthermore, it demonstrates that from 774 (at 100 Hz) to 21 (at 1 MHz) with simultaneous decrease of to 0.13 (at 1 MHz). The decrement of
as well as
decreases
from 2.4 (at 100 Hz)
with increasing frequency ensures the
ferroelectric nature of the FSB. However, the dielectric response of the FSB is almost independent of the frequency in higher frequency range (
Hz) and this is indicative for
dipolar polarization behavior. Therefore, it possesses a superior piezoelectric charge co-efficient, d33 ~ 22 pC/N (Supporting Information, Figure S3) and a converse piezoelectric coefficient, = 0.028 Vm/N. These values are comparable with scleral collagen [15]. The superior piezoelectric strength can be attributed to the layer by layer arrangement of the collagen nanofibrils and self-polarized amide bond in the FSB collagen (Figure 2e,f). Finally, we have fabricated an energy harvester termed as nanogenerator and named BPNG. The experimentally measured (Figure 4a) rectified open-circuit dc output voltages (VRoc) and short circuit currents (IRsc) generated by the BPNG under different applied stresses of human finger are shown in Figure 4b. The applied stresses ( ) were estimated depending on the generated strain (ε) within the FSB and the output voltages from the BPNG as,
|
|
where,
L is the thickness (~ 253 μm) of the FSB (Supporting Information, associate discussion S1) [7]. The BPNG exhibits
with
% s-1 and increased to
under with
with a strain rate of 1.34
(Supporting information, Figure S4 and with a strain rate of 6.72 % s−1
Video S1) when the BPNG is subjected to (Supporting information, Table S1). Interestingly, the
as well as the
show almost linear
dependencies with the applied stresses (inset of Figure 4b). Theoretically,
ε̇ , where, A~217 mm2 is the total effective
on the piezoelectric coefficients as,
area, ̇ is the applied strain rate (Supporting Information, Table S1) and Young’s modulus [7, 34]. Thus, theoretically, corresponding to
and
linearly depends
and
is the can be generated
(Supporting information, associate discussion S2
and table S2). The deviation of the experimental results from theoretical prediction is presumably
due to the charge loss in the FSB as evident in the dielectric study (Figure 3d). In order to indentify whether the signal is the true electrical output response due to piezoelectric property, widely accepted switching polarity test was performed upon reversing the output connection (Supporting information, Figure S5) [35]. In this case, the magnitude of the output voltages are same but opposite in polarity. Furthermore, under forward and reverse connection, the magnitude in peak output voltage between compress and release conditions (i.e., positive and negative peaks) are detected to be different due to the difference in straining rate when applying and releasing the stress on the BPNG [36]. Additionally, to confirm that the large output voltage is produced from the FSB, only PDMS based device (without FSB) was also fabricated under identical condition and its output voltage was carefully measured. A negligible output voltage (~ 0.01 V) is obtained (Supporting Information, Figure S6) under the mechanical stress of 1.4 MPa. These observations rule out any visible contribution of the artefacts or friction as a source of the output electrical signals from the BPNG. Basically, electricity generation in the BPNG involves piezoelectric mechanism where an electric field is generated within the FSB under mechanical deformation and the opposite charges are induced in the top and bottom electrodes. As a result, current can only flow through the external load because the FSB is a dielectric material (Figure 3d) and a positive output voltage is obtained during the stress application (Figure 4c(i) and Supporting information, inset of Figure S7). When the deformation diminishes, the built-in potential is faded out and an opposite potential is formed due to the flow of free charges in the opposite direction to balance the accumulated charges at both ends of the external circuit (Figure 4c(ii) and Supporting information, Figure S7). It has been found that the BPNG reacts very quickly with increasing stresses (Supporting information, Figure S7). To provide more insights on the working principle, the distribution of the generated charges under 1.4 MPa stress within
the FSB is shown by simulation (Figure 4d), performed via finite element method (FEM) (detail discussion is provided in supporting information, associate discussion S3). The calculated piezo– potential is consistent with our experimental observation (Figure 4b). The resulting deformation (i.e., displacement) distribution of the BPNG at the external stress amplitude of 1.4 MPa is shown in the supporting information (Figure S8). Interestingly, the maximum deformation under the compressive normal stress of 1.4 MPa is very large (~ 5 µm). In FSB, though the selfassembled peptide bonds are in compact form but still the air gap between the fibers is present which makes the FSB porous and soft. This behavior yield considerably higher displacement leading to an increased piezoelectric potential. To date, the origin of piezoelectricity in biomaterials is not completely revealed because they possess unusual behaviour and do not follow the classic models of piezoelectric theories based on idealized, crystalline structures. However, according to recent finding, the individual type I collagen fibril exhibit shear piezoelectricity due to the presence of N and C terminal telopeptides and C6 symmetry [19]. In contrast, a collection of ordered collagen fibril present in FSB, exhibits a complete different behaviour as we have noticed. Previously, this kind of difference was also observed in M13 bacteriophage [20]. The possible explanation for such kind of behaviour, as suggested recently [37], is that the application of compressive stress on the compact and ordered collagen causes neighbouring α helices on the collagen surface to rub against each other, possessing intrapolypeptide –CONH hydrogen bonding motif. This results in the deformation of the triple helical structure and new electric dipole moments are developed. As the FSB possess layer by layer arrangement of the collagen nano-fibrils (Supporting Information, Figure S2) the generation of electric dipole moments due to their internal rubbing is large under applied stress [37]. Another suggested possible explanation is that [37], as collagen possesses C6 symmetry, the compressive
deformation could break this symmetry and subsequently produce new charges on the top and bottom surfaces of the FSB. In this case, these effects are amplified by the presence of interpolypeptide –CONH hydrogen bonding motif being formed between the polypeptide chains of neighbouring α helices in the highly oriented collagen crystal (Figure 4e) [12,13]. More substantially, the enhancement of the piezoelectric response in the FSB associated to the cooperative electromechanical mutual interaction among the self-aligned adjacent fibers during applied pressure compared to single fiber [19, 38]. Thus, it is quite expected and desirable that the FSB shows longitudinal piezoelectric effect. To further investigate the ultra sensitivity of the BPNG, it was arranged as a vibration sensor by mounting it in cantilever arrangement (left upper inset of Figure 5a). It allows the BPNG to vibrate freely under each finger striking from 3 cm of height. Therefore, each gentle finger striking generates open circuit voltage of 3 V (Figure 5a). The damping behavior in the output performance again signifies the piezoelectric characteristics of the BPNG [39]. Fitted amplitude of the single output using exponential function, results the damping factor,
(where t is time)
of 15.8 (right upper inset of Figure 5a) which is comparable with
the ZnO based piezoelectric nanogenerator [39]. The BPNG also responses well under the machine vibration (i.e., imparted periodically with the cylindrical stepper motor probe of portable sewing machine as demonstrated previously) [8] and generates Voc ~ 3.6 V with proper reversibility (Figure 5b) under
~ 0.5 MPa. The fatigue test of the BPNG has been performed
by recording the output voltage as a function of time over extended cycling times (1800 cycles) under 0.75 MPa compressive stress by human finger tapping, indicates the long term stability of BPNG (Figure 5c). To investigate the potential applicability of the BPNG commercially available capacitor of 10 μF capacitance was connected to the BPNG via full wave bride rectified
circuit and charged up under repeated applied stress (Figure 5d). The low time constant value (τ ~ 169 s) ensures the rapid energy supply ability of the BPNG. Thus, we have successfully stored 28.9 μJ energy delivered by the BPNG across a 10 μF capacitor. In case of normal animals, the minimum external electric energy required for triggering the action potential of the artificially contracted heart is 1.1 µJ [3, 40]. Thus, quick and sufficient charge generating capability enables the BPNG to be applicable for biomedical sensor fabrication and interfacing with human body parts. Furthermore, the bridge rectified output voltage and current are measured as a function of the external load resistance ranging from 100 kΩ to 40 MΩ (Figure 5e and Supporting Information, Figure S9). The instantaneous voltage drop across resistances supplied by the BPNG gradually increases with the increment of the resistance, and saturates at an extremely high resistance (~ 40 MΩ) corresponding to the open-circuit voltage. In contrast, short-circuit current outputs are gradually decreased from the saturated short–circuit current upon increasing the load resistance (Figure 5e). The BPNG is able to deliver a maximal instantaneous power density (calculated by across load resistance
, where, A is the effective contact area,
is the voltage drop
respectively) of 4.15 μW/cm2 across 9 MΩ load resistance (Figure 5f).
At this condition, piezoelectric energy conversion efficiency (
) of BPNG is 0.3 %
(Supporting information, associate discussion S4). Thus, the BPNG drive several colored LEDs such as blue, green, red and also white separately where external batteries are not used (Supporting information, Video S2). Particularly, the BPNG lit up a series of 55 blue LEDs (inset of Figure 5f and) proving the efficiency and utility of BPNG in portable electronic system. It is evident from the current (I)–voltage (V) characteristic of a single blue LED that the output current (IRsc) of 51 nA is sufficient enough to turn on the blue LED. As 55 LEDs are in series connection, so all LEDs experience same amount of current and glow simultaneously. Since, the
resistance of the LED is very low which is far below than the load resistance where the rapid change of IRsc has been observed (Figure 5e). So, the current across 55 LEDs is almost the same as IRsc. Another important point is that the maximum power output of BPNG is observed across 9 MΩ load resistance and the resistance of a single blue LED is far below the maximum power point [41]. So, BPNG is enabling to flash the 55 LEDs connected in series. Basically, BPNG can be considered as a charge (q) source in parallel with an internal capacitor (Ci) and a resistor (Ri) (inset of Figure 5d). Therefore, BPNG acts as a good power source under mechanical impact and the outputs fit well with linear circuit theory which evaluates the value of internal resistance, Ri ~ 4.55 MΩ (Supporting Information, Figure S10 and associated discussion S6). According to the RC circuit model, the evaluated internal capacitance of the BPNG is 27 μF (Supporting Information, associate discussion S7). Thus, low internal resistance with higher capacitance makes the BPNG more suitable power source for its potential application in flexible portable electronic devices [42]. More importantly, the output voltage of BPNG is very much stable irrespective of environmental variation as we have tested over 18000 cycles up to 90 days (Figure 6a). In addition, the BPNG was also capable to sense and harvest mechanical energy arises during normal walking and football playing motions (Figure 6b). Thus, biomechanical assessments for musculoskeletal injuries and anthropometry can be performed in self-powered mode using BPNG depending on age, height and body mass of sports person and workers [43]. In overall, our BPNG is very much comparable and even superior in some cases with the previously reported bio–piezoelectric materials (Supporting Information, Table S3). 4. Conclusion In summary, we developed fish collagen, a natural resource based robust nanogenerator, i.e., biopiezoelectric nanogenerator (BPNG) posses several merits. It is capable of producing an open-
circuit voltage of 10 V and short–circuit current of 51 nA under a compressive normal stress of 1.4 MPa with theoretical validation. It can also generates outstanding power density of 4.15 μW/cm2 with its inherent high piezoelectric energy conversion efficiency of ~ 0.3 %. With these merits, the BPNG potentially offers a broad range of applications ranging from biomedicine to electronic skin sensors in robotics and for the development of self-powered portable electronic systems. Due to the biocompatibility of the collagen fibril, the potential use of the BPNG as biomedical sensors is quite expected where the implantation of the BPNG in a living body is possible to harvest energy from different bio signals such as respiration, heartbeat, blood circulation etc. Associated Content Supporting Information Additional information on, detail discussions on material characterizations and nanogenerator fabrication process, UV-vis absorption spectra, cross-sectional image, measured d33 value, and dielectric spectra of FSB are given. In addition, theoretical calculation of applied stress, current measurement, fatigue test, theoretical simulation, calculated energy conversion efficiency, internal resistance and several vibrational responses from the BPNG are also elaborately given.
Author Information Funding Sources This work was financially supported by a grant from the Science and Engineering Research Board (SERB/1759/2014−15), Government of India.
The authors declare no competing financial interest.
Acknowledgements This work was financially supported by a grant from the Science and Engineering Research Board (SERB/1759/2014-15), Government of India. Authors are also grateful to DST, Govt. of India for their helping hand to develop the instrumental facilities under FIST-II programme and for awarding INSPIRE fellowship (IF130865) to Mr. Sujoy Kumar Ghosh. We acknowledge to Mr. Samiran Garain for his skilful FE-SEM operation. Authors also thank for the support from Dr. Karsten Henkel (BTU Cottbus-Senftenberg, Angewandte Physik-Sensorik, K.-WachsmannAllee 17, 03046 Cottbus, Germany) and Mr. S.P. Mandal for their valuable suggestions while preparing manuscript. We are thankful to Dr. D. K. Shukla and Dr. D. M. Phase for availability and measurement of NEXAFS. We also acknowledge help from Mr. Rakesh Kumar Sah during NEXAFS measurements. We also greatly acknowledge to Dr. Shrabanee Sen (Scientist, Sensor and Actuator Division, Central Glass and Ceramic Research Institute (CSIR)) for helping d33 measurement.
Conflict of interest The authors declare no competing financial interest.
References [1] Z. L. Wang, J. Song, Science 312 (2006) 242–246. [2] Z. Li, G. Zhu, R. Yang, A. C. Wang, Z. L. Wang, Adv. Mater. 22 (2010) 2534–2537.
[3] G. T. Hwang, H. Park, J. H. Lee, S. Oh, K. I. Park, M. Byun, H. Park, G. Ahn, C. K. Jeong, K. No, H. Kwon, S. G. Lee, B. Joung, K. J. Lee, Adv. Mater. 26 (2014) 4880–4887. [4] M. M. Alam, S. K. Ghosh, A. Sultana, D. Mandal, Nanotechnology 26 (2015) 165403. [5] J. Yan, Y. G. Jeong, ACS Appl. Mater. Interfaces 8 (2016) 15700−15709. [6] F. R. Fan, W. Tang, Z. L. Wang, Adv. Mater. 28 (2016) 4283–4305. [7] S. K. Ghosh, T. K. Sinha, B. Mahanty, D. Mandal, Energy Technol. 3 (2015) 1190–1197. [8] A. Tamang, S. K. Ghosh, S. Garain, M. M. Alam, J. Haeberle, K. Henkel, D. Schmeisser, D. Mandal, ACS Appl. Mater. Interfaces 7 (2015) 16143−16147. [9] C. Ribeiro, V. Sencadas, D. M. Correia, S. Lanceros-Mendez, Colloids and Surfaces B: Biointerfaces 136 (2015) 46–55. [10] Y. Kanzaki, F. Terasaki, M. Okabe, S. Fujita, T. Katashima, K. Otsuka, N. Ishizaka, Circulation 122 (2010) 1973–1974. [11] K. A. Piez, J. Gross, J. Biol. Chem. 235 (1960) 995–998. [12] A. Rich, F. H. C. Crick, J. Mol. Biol. 3 (1961) 483–506. [13] R. D. B. Fraser, T. P. Macrae, E. Suzuki, J. Mol. Biol. 129 (1979) 463–481. [14] H. Athenstaedt, Nature 228 (1970) 830–834. [15] S. Ghosh, B. Z. Mei, V. Lubkin, J. I. Scheinbeim, B. A. Newman, P. Kramer, G. Bennett, N. Feit, J. Biomed. Mater. Res 39 (1998) 453–457. [16] S. Mascarenhas, Electrets: chap.6. Bioelectrets: Electrets in Biomaterials and Biopolymers, Springer-Verlag, Berlin, 1987. [17] E. Fukada, Electr. Insul. IEEE Trans. 27 (1992) 813–819. [18] E. Fukada, I. Yasuda, Jpn. J. Appl. Phys. 3 (1964) 117–121.
[19] M. M. Jolandan, M. F. Yu, Nanotechnology 20 (2009) 085706. [20] B. Y. Lee, J. Zhang, C. Zueger, W. J. Chung, S. Y. Yoo, E. Wang, J. Meyer, R. Ramesh, S.W. Lee, Nat. Nanotech. 7 (2012) 351–356. [21] S. J. Kim, D. B. Jeon, J. H. Park, M. K. Ryu, J. H. Yang, C. S. Hwang, G. H. Kim, S. M. Yoon, ACS Appl. Mater. Interfaces 7 (2015) 4869–4874. [22] J. W. Donovan, in: Physical Principal and Techniques of Protein Chemistry (Part A), Academic Press, New York, 1969, pp. 101-102. [23] B. Wu, C. Mu, G. Zhang, W. Lin, Langmuir 25 (2009) 11905–11910. [24] B. G. Frushour, J. L. Koenig, Biopolymers 14 (1975) 379–391. [25] J. H. Muyongaa, C. G. B. Cole, K. G. Duodu, Food Chem. 85 (2004) 81–89. [26] L. Wang, Q. Liang, T. Chen, Z. Wang, J. Xu, H. Ma, Food Hydrocolloids 38 (2014) 104– 109. [27] O. Kaewdang, S. Benjakul, T. Kaewmanee, H. Kishimura, Food Chem. 155 (2014) 264– 270. [28] J. St ̈ hr, NEXAFS Spectroscopy, Springer–Verlag, Berlin, 1992. [29] M. L. Gordon, G. Cooper, C. Morin, T. Araki, C. C. Turci, K. Kaznatcheev, A. P. Hitchcock, J. Phys. Chem. A 107 (2003) 6144–6159. [30] Y. Zubavichus, A. Shaporenko, M. Grunze, M. Zharnikov, J. Phys. Chem. A 109 (2005) 6998–7000. [31] B. G. Baraskar, S. G. Kakade, A. R. James, R. C. Kambale, and Y. D. Kolekar, AIP Conf. Proc. 1731, 140066 (2016). [32] T. Furukawa, and N. Seo, Jpn. J. Appl. Phys. 29, 675 (1990).
[33] H. S. Nalwa, Handbook of Low and High Dielectric Constant Materials and Their Applications, Academic Press, London, 1999. [34] M. A. Nawaz, Degree Thesis on Material and Acoustic Properties of Swim bladders of Tilapia and Channel Catfish. Diss. Virginia Commonwealth University Richmond, Virginia, 2005. [35] R. Yang, Y. Qin, C. Li, L. Dai, Z. L. Wang, Appl. Phys. Lett. 94 (2009) 022905. [36] J. H. Jung, M. Lee, J. Hong, Y. Ding, C. Y. Chen, L. J. Chou, Z. L. Wang, ACS Nano 5 (2011) 10041–10046. [37] S. M. Yu, Nat. Nanotech. 7 (2012) 343–344. [38] L. Persano, C. Dagdeviren, C. Maruccio, L. D. Lorenzis, D. Pisignano, Adv. Mater. 26 (2014) 7574–7580. [39] A. Yu, P. Jiang, Z. L. Wang, Nano Energy 1 (2012) 418–423. [40] T. E. Starzl, R. A. Gaertner, R. C. Webb Jr., Circulation 11 (1955) 952–962. [41] S. Wang, L. Lin, Z. L. Wang, Nano Lett. 12 (2012) 6339–6346. [42] S. Niu, S. Wang, L. Lin, Y. Liu, Y. S. Zhou, Y. Hu, Z. L. Wang, Energy Environ. Sci. 6 (2013) 3576–3583. [43] P. Madeleine, A. Samani, M. Zee, U. Kersting, Biomechanical Assessments in Sports and Ergonomics, Theoretical Biomechanics, Dr Vaclav Klika (Ed.), ISBN: 978-953-307-851-9, InTech, 2011.
(a)
(b) (c)
Fig 1. Collection and preparation of the FSB for electrical characterization (a) The photograph of the sweet water (Catla Catla) fish from where (b) the swim bladder was collected to be used in this study. (c) The flexibility of the fish swim bladder (FSB) with sputtered Au electrodes was demonstrated by human finger.
(b)
(c)
(e)
(d)
(f)
Fig 2. The structural characterization of the fish swim bladder (FSB). (a) FE-SEM image with left inset representing a single collagen fiber to calculate the D-periodicity indicated by the histogram profile in the right inset, (b) WAXD pattern in the range of 2θ ~ 5o–70o, (c) Raman spectrum in the region of 1800–800 cm-1, (d) ATR-FTIR spectrum in 4000–1000 cm-1 region. Angular dependent NEXAFS spectra (normalized) of (e) N K-edge and (f) O K-edge spectra. Inset shows the incident beam geometry with respect to the FSB and degree of linear dichroism (%) as a function of incident beam direction, θ.
(a)
(b)
(c)
(d)
Fig 3. (a) Standard polarization (P)–electric field (E) hysteresis loop and (b) the corresponding strain (S)–electric field (E) hysteresis loop of FSB under the electric field of
with
frequency of 1 kHz. (c) The S versus P2 plot. (d) Frequency dependent dielectric spectra in the frequency range of 100 Hz– 1MHz.
6
VRoc (V)
4
10
2 0
0.3 0.6 0.9 1.2 1.5
50 40 30 20 10 0
IRsc (nA)
VRoc (V)
15
(b)108
1.4 MPa
Stress (MPa)
0.75 MPa
5 0.28 MPa
0
0
(c) (i)
(ii)
(e)
2
(d)
4
Time (s)
Stress
6
Fig 4. Characterizations of the BPNG. (a) Operation demonstration of the BPNG for mechanical energy harvesting by finger impact. (b) The rectified output voltages from the BPNG by different stresses with stress dependent output voltages and currents in inset. (c) Schematic illustration of the mechanism involved in the energy harvesting performance of the BPNG under stress impact and release motion. (d) The simulated charge distribution FEM model inside the BPNG under 1.4 MPa stress. (e) The schematic illustration of intra- and inter-peptide chains of collagen with Gly-Pro-Hyp amino acids motif sequence to understand the origin of polarization in the FSB.
(a)
(b)
𝛽
𝑒
𝛽𝑡
(c)
(d)
(e)
(f)
Fig 5. Several applications of the BPNG (a) The output response of the BPNG as a vibration sensor after several excitations. Left upper inset shows the schematic of the experimental set up. Right upper inset shows the close view of the output response during one excitation with its fitting amplitude by exponential function. (b) The machine vibration response of the BPNG with proper dipole reversibility (right upper inset) using a simple portable swing machine (left upper inset). (c) The stability test of the BPNG under 0.75 MPa stress by human finger tapping (The horizontal red dotted lines serve as guides to the eye). (d) Fast capacitor charging performance of the BPNG is demonstrated. The inset shows the schematic circuit diagram used to charge 10 µF capacitor (e) Dependences of output voltage and current on variable external load resistance. (f) Instantaneous output power density of the BPNG as a function of variable load resistance. The inset shows an array of 55 blue LEDs in series displaying ‘ONPDL’, an array of 22 serial connected green LEDs representing ‘JU’ as well as one red and one white LED which are instantly turned on by the electricity generated from the BPNG. The real-time I−V characteristic of a single blue LED from its OFF state to ON state is shown in the inset.
(a)
(b)
Fig 6. (a) The mechanical durability test of BPNG over 18000 cycles up to 90 days. (b) The pulse output voltages from the BPNG when it was impacted by different parts of foot during normal walking, pushing and juggling by football. Author Biography
Mr. Sujoy Kumar Ghosh is pursuing PhD from Department of Physics, Jadavpur University, India. He received his M.Sc and B.Sc. degree in physics from Jadavpur University in 2012 and 2010 respectively. His research interest includes polymer based piezo-, pyro- and ferro-electric energy harvester and synthesis piezoelectric nanomaterial.
Dr. Dipankar Mandal is an Assistant Professor in the Department of Physics, Jadavpur University, India. He completed his M.Sc. in 2002 from Jadavpur University and M.Tech. in
2004 from Indian Institute of Technology, Kharagpur. He received his PhD in 2008 from BTU Cottbus, Germany. His research interest focused on advanced functional materials, polymer electronics, piezoelectric and ferroelectric polymers, sol-gel chemistry, semi-conducting materials, biosignal monitoring using various types of nano invasive biosensors, polymeric nanogenerator, metal nanoparticles, rare-earth doped glass.
Video S1: The bridge rectified peak output current,
measurement of BPNG by periodical
human finger impact from different heights. Video S2: A series of 55 commercial blue LEDs directly driven by BPNG. Furthermore, several colour LEDs such as 22 green, one red and one white LED are directly operated by BPNG.
Graphical Abstract
Highlights
The direct fabrication of an efficient bio-piezoelectric nanogenerator (BPNG) from fish (Catla Catla) swim bladder (FSB).
The self-alignment of the molecular dipoles in the FSB collagen is confirmed by the angular dependent Near edge X-ray Absorption Spectroscopy (NEXAFS). The large piezoelectric charge coefficient ( ~ 22 pC/N) enables the BPNG to generate the open-circuit voltage of 10 V and short-circuit current of 51 nA under compressive normal stress (~ 1.4 MPa) by human finger. The high power throughput of 4.15 μW/cm2 with inherent piezoelectric energy conversion efficiency (~ 0.3%). Furthermore, the BPNG instantly turns on more than 50 commercial blue LEDs which are unable to drive by a battery of 8.66 V. For real time demonstration we have also provided the associated video files mentioned in the supporting file.
Graphical Abstract
Efficient Natural Piezoelectric Nanogenerator: Electricity Generation from Fish Swim Bladder Sujoy Kumar Ghosh and Dipankar Mandal*
Organic Nano-Piezoelectric Device Laboratory (ONPDL), Department of Physics Jadavpur University, Kolkata 700032, India *
Corresponding author. Tel.: +91 33 2414 6666x2880; fax: +91 33 2413 8917
E-mail address: [email protected] TOC Graphic
Green and clean energy harvesting via fabrication of a bio-degradable and bio-compatible piezoelectric nanogenerator i.e., bio-piezoelectric nanogenerator (BPNG) from waste fish byproducts is spot lighted through one step process.