- Email: [email protected]
Silver foils diffraction limit
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NEWS University of Mining and Metallurgy, Dresden’s University of Technology, Bonemaster Gesellschaft fuer Biokompatible System mbH and France’s National Centre of Scientific Research and Department of Energy Techniques and Environmental Performance. It will work to synthesise new and better catalysts from recovered SPMs. The proposed route combines two biotechnologies for clean SPM recovery, with concomitant bulk biosynthesis of new bio-nano-crystal catalytic materials. For more information contact: Dr Ian Dalrymple, C-Tech Innovation Ltd, Capenhurst Technology Park, Chester CH1 6EH, UK. Tel: +44 151 347 2908. Email: [email protected]
Spintronics achieve NOT UK’s Durham University scientists claim a major advance carrying out a basic computer function using a magnetic microchip. The researchers have taken the next step to the magnetic storage of information, by using a magnetic chip to perform the fundamental NOT operation that converts a nought to a one and vice versa. The technology uses electron spin, creating a north and south pole, that in conventional electronics is made by switching between high and low voltages. Research team leader, Dr Russell Cowburn, said: ‘There is still some way to go, but the potential is there to create a whole new technology based on magnetism rather than electricity.’ For more information contact: Dr Russell Cowburn, Department of Physics, University of Durham, Rochester Building, South Road, Durham DH1 3LE, UK. Tel: +44 191 374 2388. Email: [email protected]
Silver foils diffraction limit Incredible optical characteristics of textured metal films are causing a rethink in optics. Physicists led by Henri Lezec and Thomas Ebbesen of Louis Pasteur University, have shown that large amounts of light can pass through a subwavelength aperture in a patterned metal film without being diffracted. This could lead to smaller photonic and electronic devices, overcoming the diffraction limit. The Strasbourg-led team has found a way to shine more light through a tiny aperture, and channel it into a collimated beam. Lezec and coworkers created a sub-wavelength aperture in a thin silver film and etched a periodic pattern of grooves around it, using a FIB. This corrugated metal surface supports the excitation of surface waves, plasmons, that soak up the incident light. Theoretical studies suggested that plasmons
6
Smart Materials Bulletin
squeeze through the hole and are converted back into light on the other side. This enhances the optical transmission of the film. The researchers found that the wavelength of the transmitted light depends on the spacing of the grooves in the film. Patterning the reverse side of the film, they also discovered that the light emerges from the hole as a tightly focused beam, that can propagate with very little divergence. The direction of the transmitted light could then be controlled by changing the symmetry of the periodic pattern. The technique may be useful in a variety of nanoelectronics applications, including optimising near-field devices for microscopy or data storage, and improving optical devices such as lightemitting diodes (LEDs) and semiconductor lasers. For more information contact: University Louis Pasteur, 4 rue Blaise Pascal, F-67070 Strasbourg, France. Tel: +33 3 9024 5000. Email: [email protected]
New hydrogel Employing a new design for hydrogels, based on protein building blocks, rather than full proteins, the University of Delaware and University of California, Santa Barbara, have developed a lightweight hydrogel. The new hydrogel is a ‘diblock copolypeptide amphiphile’ that can rearrange itself quickly after the removal of mechanical stress. The polymer is based on amino acids, that contains hydrophilic and hydrophobic chemical building blocks. Placed in solution, such a combination usually forms a micelle, a star-like polymer with hydrophobic constituents huddled inside and hydrophilic components stretching outwards. But the researchers gave the hydrophobic molecules a special, helical shape, that caused the compound to form a dilute, porous hydrogel in solution. In addition to giving it a fast response time, the dilute and highly porous nature of this hydrogel open up new biotechnological uses. For more information contact: Darrin Pochan, University of Delaware, USA. Email: [email protected] Or contact: Timothy Deming, UC-Santa Barbara, USA. Email: [email protected]
SmartShirts emerging Sensatex SmartShirts, a combination of textile innovation and wireless engineering, could be on the market by September. The shirts can monitor the body’s vital signs, help in training athletes or protect wearers in dangerous situations. The garments can monitor heart and respiration rate, calories burn and temperature transmitting these to a laptop via a
wireless transceiver for collation and analysis. The SmartShirt makers are also developing the clothing to protect emergency rescue workers with positioning devices fitted to help track their location. Eventually, the system will detect the extent of falls, the presence of hazardous gases, offer two-way voice communication, or deduce location of gunshot wounds. Sensatex fabric was developed by researchers at the Georgia Institute of Technology’s School of Textile and Fiber Engineering and the Defense Advance Research Projects Agency. The idea was to create a fabric that could assist soldiers, being able to monitor health and safety, as well as change colour to aid in camouflage, and detect the presence of noxious chemicals or biological threats. The smart textiles can be fully integrated with materials, such as cotton, Lycra or silk. Blended, they take the form of the original fabric. For more information contact: Sensatex, 494 Broadway, 2nd Floor, New York, NY 10012, USA. Tel: +1 212 334 2525. Email: [email protected]
Template wetting technique A joint German research team from Philipps University and the Max Planck Institute of Microstructure Physics believes that its template-wetting technique could provide customised nanotubes for a broad range of nanoscience applications. The team fabricate polymer nanotubes with monodispersed size distribution and uniform orientation. When either a polymer melt or solution is placed on a substrate with high surface energy, it spreads to form a thin film. A similar wetting phenomenon occurs if porous templates are brought into contact with a polymer solution or melt. A thin surface film develops, covering the pore walls. This surface covering process operates on a timescale ranging from a few minutes to half an hour. The pores are not filled due to thermal quenching in the case of melts or solvent, or evaporation in the case of solutions. This maintains the nanotube structure. The template dictates the formation and orientation of the nanotubes, so ordered polymer nanotube arrays can be obtained. According to the team, the approach should be a promising route towards functionalised polymer nanotubes. For more information contact: Max-PlanckGesellschaft zur Förderung der Wissenschaften eV, Generalverwaltung, Postfach 101062, D-80084 München, Germany. Tel: +49 89 2108-0. Email: [email protected]
July 2002
7/15/02
3:41 PM
Page 6
NEWS University of Mining and Metallurgy, Dresden’s University of Technology, Bonemaster Gesellschaft fuer Biokompatible System mbH and France’s National Centre of Scientific Research and Department of Energy Techniques and Environmental Performance. It will work to synthesise new and better catalysts from recovered SPMs. The proposed route combines two biotechnologies for clean SPM recovery, with concomitant bulk biosynthesis of new bio-nano-crystal catalytic materials. For more information contact: Dr Ian Dalrymple, C-Tech Innovation Ltd, Capenhurst Technology Park, Chester CH1 6EH, UK. Tel: +44 151 347 2908. Email: [email protected]
Spintronics achieve NOT UK’s Durham University scientists claim a major advance carrying out a basic computer function using a magnetic microchip. The researchers have taken the next step to the magnetic storage of information, by using a magnetic chip to perform the fundamental NOT operation that converts a nought to a one and vice versa. The technology uses electron spin, creating a north and south pole, that in conventional electronics is made by switching between high and low voltages. Research team leader, Dr Russell Cowburn, said: ‘There is still some way to go, but the potential is there to create a whole new technology based on magnetism rather than electricity.’ For more information contact: Dr Russell Cowburn, Department of Physics, University of Durham, Rochester Building, South Road, Durham DH1 3LE, UK. Tel: +44 191 374 2388. Email: [email protected]
Silver foils diffraction limit Incredible optical characteristics of textured metal films are causing a rethink in optics. Physicists led by Henri Lezec and Thomas Ebbesen of Louis Pasteur University, have shown that large amounts of light can pass through a subwavelength aperture in a patterned metal film without being diffracted. This could lead to smaller photonic and electronic devices, overcoming the diffraction limit. The Strasbourg-led team has found a way to shine more light through a tiny aperture, and channel it into a collimated beam. Lezec and coworkers created a sub-wavelength aperture in a thin silver film and etched a periodic pattern of grooves around it, using a FIB. This corrugated metal surface supports the excitation of surface waves, plasmons, that soak up the incident light. Theoretical studies suggested that plasmons
6
Smart Materials Bulletin
squeeze through the hole and are converted back into light on the other side. This enhances the optical transmission of the film. The researchers found that the wavelength of the transmitted light depends on the spacing of the grooves in the film. Patterning the reverse side of the film, they also discovered that the light emerges from the hole as a tightly focused beam, that can propagate with very little divergence. The direction of the transmitted light could then be controlled by changing the symmetry of the periodic pattern. The technique may be useful in a variety of nanoelectronics applications, including optimising near-field devices for microscopy or data storage, and improving optical devices such as lightemitting diodes (LEDs) and semiconductor lasers. For more information contact: University Louis Pasteur, 4 rue Blaise Pascal, F-67070 Strasbourg, France. Tel: +33 3 9024 5000. Email: [email protected]
New hydrogel Employing a new design for hydrogels, based on protein building blocks, rather than full proteins, the University of Delaware and University of California, Santa Barbara, have developed a lightweight hydrogel. The new hydrogel is a ‘diblock copolypeptide amphiphile’ that can rearrange itself quickly after the removal of mechanical stress. The polymer is based on amino acids, that contains hydrophilic and hydrophobic chemical building blocks. Placed in solution, such a combination usually forms a micelle, a star-like polymer with hydrophobic constituents huddled inside and hydrophilic components stretching outwards. But the researchers gave the hydrophobic molecules a special, helical shape, that caused the compound to form a dilute, porous hydrogel in solution. In addition to giving it a fast response time, the dilute and highly porous nature of this hydrogel open up new biotechnological uses. For more information contact: Darrin Pochan, University of Delaware, USA. Email: [email protected] Or contact: Timothy Deming, UC-Santa Barbara, USA. Email: [email protected]
SmartShirts emerging Sensatex SmartShirts, a combination of textile innovation and wireless engineering, could be on the market by September. The shirts can monitor the body’s vital signs, help in training athletes or protect wearers in dangerous situations. The garments can monitor heart and respiration rate, calories burn and temperature transmitting these to a laptop via a
wireless transceiver for collation and analysis. The SmartShirt makers are also developing the clothing to protect emergency rescue workers with positioning devices fitted to help track their location. Eventually, the system will detect the extent of falls, the presence of hazardous gases, offer two-way voice communication, or deduce location of gunshot wounds. Sensatex fabric was developed by researchers at the Georgia Institute of Technology’s School of Textile and Fiber Engineering and the Defense Advance Research Projects Agency. The idea was to create a fabric that could assist soldiers, being able to monitor health and safety, as well as change colour to aid in camouflage, and detect the presence of noxious chemicals or biological threats. The smart textiles can be fully integrated with materials, such as cotton, Lycra or silk. Blended, they take the form of the original fabric. For more information contact: Sensatex, 494 Broadway, 2nd Floor, New York, NY 10012, USA. Tel: +1 212 334 2525. Email: [email protected]
Template wetting technique A joint German research team from Philipps University and the Max Planck Institute of Microstructure Physics believes that its template-wetting technique could provide customised nanotubes for a broad range of nanoscience applications. The team fabricate polymer nanotubes with monodispersed size distribution and uniform orientation. When either a polymer melt or solution is placed on a substrate with high surface energy, it spreads to form a thin film. A similar wetting phenomenon occurs if porous templates are brought into contact with a polymer solution or melt. A thin surface film develops, covering the pore walls. This surface covering process operates on a timescale ranging from a few minutes to half an hour. The pores are not filled due to thermal quenching in the case of melts or solvent, or evaporation in the case of solutions. This maintains the nanotube structure. The template dictates the formation and orientation of the nanotubes, so ordered polymer nanotube arrays can be obtained. According to the team, the approach should be a promising route towards functionalised polymer nanotubes. For more information contact: Max-PlanckGesellschaft zur Förderung der Wissenschaften eV, Generalverwaltung, Postfach 101062, D-80084 München, Germany. Tel: +49 89 2108-0. Email: [email protected]
July 2002