- Email: [email protected]
‘Smart’ consumer goods
'Smart' consumer goods By Clifford M. Friend & Christopher C. Thorpe, Cranfield University, UK 'Smart' technologies, which encompass both 'smart' materials and structures, are creating a seachange in engineering practice. Their fusion of conventional structural materials with aspects
almost 'love-like' feelings towards inanimate objects such as cars. [1] of information technology, offers the prospect of engineering systems which can sense their Cognitive aspects, on the other hand, arise local environment, interpret changes in this environment and respond appropriately. from individuals' response to their environment, Demonstrator projects exist world-wide exploring the range of possible applications for 'smart' including objects, and how from this perspective technologies in sectors ranging from aerospace and civil engineering to automobile and marine. the physical form of objects can 'afford' or 'force' A common feature of such programmes is their use of relatively sophisticated technologies, a particular behaviour.[2] examples including the use of fibre optic techniques for sensing and actuation based on Couched in these terms this again seems functional materials such as piezoceramics, electro- and magnetostrictives and shape-memory strange. However, one need only have 'pushed' a alloys. The use of such advanced technologies is symptomatic of the strong technology push door marked 'pull' to understand that the which has dominated the development of this field. physical form of an object as simple as a door handle can 'afford' a response (that is pushing) The novelty aspects of adaptive materials despite the door's 'obvious' mode of operation such as thermochromic materials and highly (communicated by the pull sign).[1] So how can the concept of 'smart' material viscoelastic plastics have also been exploited in There is no doubt that the development of products ranging from packaging and tee shirts systems enhance both aspects of a product? A major commercial issue in the design of 'smart' technologies have been technology to children's toys and mountain bikes. domestic products is differentiation, that is how The applications illustrated lie at almost pushed. However, as development of these to make a product 'stand out' amongst its systems has improved, there is an increasing need opposite ends of the 'smart' spectrum, the competitors. to match enabling technologies to the true former being examples of technology push into In a traditional commodity market such as the consumer goods sector and the latter requirements of a given application sector. consumer goods, this is usually done on price (the This has not only focussed on the appro- exploiting little more than the novelty of the lowest price!) but if one also understands the nature priateness of certain advanced technologies in materials, with no real integration into the true of user/object interactions, in particular emotional particular sectors - such as fibre optic sensing in design issues of the products themselves. interactions, these too can be used to differentiate. So how could a 'smart' design approach, the built environment, but also on the wider From a product design viewpoint underissue of whether 'smart' technology is truly a integrated with novel functional materials, create standing user/object interactions, such as cogcollection of technologies, or instead a new new and improved consumer goods? The key in sectors ranging from domestic ' nitive aspects, also enables one to design better paradigm for the design of products and systems. The latter is an important issue, since consumer goods to consumer healthcare consumer products with improved market recognition that products can be adaptive offers products is in the way 'smart' design can improve segmentation and high levels of user satisfaction. It is this interface between user/object new design options in a wider range of non- user/product interaction. For example, our homes are full of 'flawed' interaction, design and adaptive materials that conventional application sectors. Adopting 'smartness' as a design paradigm therefore creates products which we have problems using or points the way to new consumer products, but it is an area that is relatively unexplored and a new range of strong application pulls for the experience little pleasure in their use. 'Smart' design offers the potential of new unfamiliar to technologists. development of further 'smart' products, such as generations of products which are more intuitive 'smart' consumer goods. to use, create pleasure and meet different user needs.
Technology push moves to application pull
'Smart' consumer goods
The application of 'smart' technologies within the consumer goods market has as yet barely been explored. Perhaps best known is the development of a number of'smart' skis. These draw on many of the technology intensive solutions developed for aerospace and automobile applications. The aim being to create skis which adapt to ambient temperature - shape memory alloys adapting the stiffness of skis to various conditions such as soft snow and ice, or damping offvibration through the use of piezoelectric shunts.
@Smart MaterialsBulletin
User/object interaction Before considering the potential of 'smart' consumer products, it is perhaps useful to explore aspects of user/product interaction. Two of the most important are emotional and cognitive interactions. Emotional aspects arise from a product's 'behaviour' which emerges during user interaction, the product creating 'pleasure'. At first sight this seems a rather strange concept, but explains why many of us have
November2002
r
~,q
FEATURE appliances and is relatively easy to manufacture by injection moulding the kettle body with a thermochromic filler; a material familiar from colour change packaging, tee-shirts and other novelty goods. However, despite its deceptive simplicity, colour change must be carefully selected to create appropriate levels of pleasure and the correct affordances during use. This is important since from a thermochromic point of view not all colour changes are possible and selected materials and a product's 'language' must be carefully optimised together. A product based on these ideas is now commercially available in the Russell Hobbs' 'Thermocolodi' kettle (Figure 2), and anecdotal user response confirms this product's strong appeal and dynamic affordances - buy one and you'll experience it for yourselfl It is also a field which has only recently begun to be explored by ourselves for clients ranging from consumer healthcare to banking products and domestic consumer goods. For example, currently affordances and 'emotion' are created by designing a product's physical form. 'Smart' material technologies offer a sea-change in this design practice. [3] Moving from passive to active materials will create new types of affordance and enhance the emotional content of consumer goods.
Dynamic visual interfaces The concept of 'smart' consumer products is perhaps best illustrated with a case study. The most well known that we have worked on is the electric kettle. How can one use 'adaptive' materials to enhance the emotional content and affordances available in a kettle? This is well illustrated by our work on a thermochromic version, where active materials are used to create a dynamic visual change during use. One of our computer models of such a kettle is shown in Figure 1, where the body colour responds to the heating of its contents. It is difficult to communicate the effect of such a dynamic change in a static image, however our work has shown that the 'pleasure' associated with this kettle is strongly enhanced by such changes, clearly differentiating the product. New affordances are also created, correctly selected colour changes producing a strong metaphor for temperature and or safety and fill levels. This relatively simple example represents a break-through product in this family of
November2002
Physical dynamic interface Our work is not restricted only to visually dynamic products. Perhaps even greater levels of emotional response can be created using physically dynamic materials. Here we are exploring products in the consumer appliance and healthcare sectors. We have been investigating polymers and gels to create physically dynamic products which respond to the 'mood' of their user, gentle handling creating a 'cuddly' low stiffness response, compared to a stiffer response on rougher handling - all achieved through enhanced levels of strain-rate sensitivity. We have already begun to uniquely explore the user value of these physically dynamic products Typical user pleasure indices for a physically dynamic appliance, the female users developing 'relationships' with the product, and the males responding to pleasures associated with the
1000
80.0
700 i
o
s o o 6 ° ° ~ 1 ~ 400
•Smart
[ ] Non-smart
30.0
20.0
10.0 O0
'mind,' 'values' and 'senses' using quantitative techniques originally developed fbr the assessment of computer interfaces. This is enabling us to not only evaluate consumers' views on usability,,but to also deconstruct the more kmdamental reasons behind their 'pleasure'.[4] This is illustrated ill Figure 3, which shows both male and female consumers' preference for 'smart' humanware products. Figure 4 also shows how one can now differentiate the origins of this 'pleasure' between consumer groups, females finding pleasure in developing 'relationships' with the products, whilst males respond to pleasures associated with the 'mind,' 'values' and "senses'. Such quantitative tools enable us to carefully tune the behaviour of" these 'smart' products so that their 'pleasure' can be optimised for the widest range of consumers. However, there are also many products whose usability would be enhanced if they were not
80
8o x
°t
•
_
.
.
.
.
.
.
.
.
.
.
1
30
320
320 ~1o ~- o -lo -20
~- o -lO -20 Female
Male PLEASURES
I
IDEO
to do with values
!
PSYCHO
to do with the mind
I
soc~o
to do with relationships
PHYSIO
to do with the bodyand senses
SmartMaterialsBulletin @
~ESEARCH TREND c. optimised to an 'average' person but that 'one size adapted to all'. The 'smart' design approach can also contribute strongly here. For example, handles that adapt uniquely to their immediate user and which also uniquely adapt to all subsequent users. These could be applied to products ranging from kitchen goods and consumer healthcare to the automotive sector. Here again highly conformable elastic materials such as elastomers and polymer gels can play a central role. Such products offer significantly enhanced usability for the old, handicapped, young, left/right-handed, with the design concept being sufficiently generic to be applied in a wide range of products. The 'smart' structures concept is attractive and entirely transferable to the consumer goods
ResearchTrends Smart performance garments The difficulties facing manufacturers of survival clothing is considered, including the need to define worst case conditions in which garments may need to afford protection. Decathlon, with a turnover of £2bn has worked closely with Leeds University to define the most important performance parameters for survival clothing. Key factors in comfort are ambient humidity and moisture management, not temperature. The design and patenting of an ultra-low spacer fabric claimed to be superior to current fleece fabrics is outlined. Detailed design of performance clothing is as important as materials used, as is subsequent testing to confirm design goals have been reached. High technology (or smart textiles in both passive form (achieved by textile design), or active form (where energy input is needed) are detailed. I Holme: Textile Horizons May/June 7-8 (2002) Survival 2002.
Shape change from AgnOxHy silver cluster on graphite induced by their chemical composition The deposition of AgnOxHy clusters onto a graphite surface, maintained at room temperature, as a function of the cluster chemical composition has been investigated. The incident clusters were produced by a gasaggregation silver cluster source when adding 0 2 and H 2 0 molecules in the carrier gas, and monitored by a time of flight mass spectrometer. Samples were imaged by electron microscopy.
Smart Materials Bulletin
market, providing that simpler technological solutions are sought which best match the requirements of the sector. The adaptivity of 'smart' products offers a new design paradigm enhancing user/product interaction through much greater emotional engagement and the use of dynamic visual and physical affordances.
Breakthrough products We have only just begun to explore the potential of 'smart' consumer products, which offer the potential of breakthrough products in a wide range of consumer goods markets. Successful development of 'smart' consumer products depends on a clear understanding of product design, user/object interaction and deep knowledge of appropriate adaptive technologies.
Results show that cluster diffusion and agglomeration on the surface as well as the resulting island morphology strongly depend on the cluster chemical composition. If the deposition of pure silver clusters leads to nano-fractal islands, a few of oxide/hydroxide molecules incorporated as impurities into the incident clusters prior to their deposition induce a post fractal island fragmentation, keeping constant the fractal dimension.Deposition of totally oxidised/hydroxided clusters induces drastic change in island morphology with a decrease of the cluster diffusion on graphite. In this case a dense nano-phase material with narrow size particle distribution in chain-like structure is obtained. C. Brdchignac, Ph. Cahuzac, E Carlier, N. Kdba'ili, J. Le Roux, A. Masson: Surface Science 518 (3) 192-200 (20 October, 2002).
Photoemission effects from Au nano clusters on TiO2 Valence level and shallow core states of Au nanoclusters on TiO2(1 1 0) have been studied by synchrotron excited photoemission. The shift to high binding energy and broadening of the Au 4f peaks with decreasing Au surface coverage can be understood in terms of decreasing cluster size and the associated effects of charge on the cluster in the final state. Shifts in the photo emission onset are more pronounced than the core level shifts and show strong dependence on the degree of reduction of the TiO2(1 1 0) substrate. This suggests that photoemission onset is influenced by initial state effect involving charge transfer from defect into cluster states. A. Howard, D. N. S. Clark, C. E. J. Mitchell, R. G. Egdell, V. R. Dhanakb: SurfaceScience518 (3) 210-224 (20 October 2002).
References 1. D.A. Norman: 'Psychology of everyday things' (Basic Books, New York, 1998). 2. J.J. Gibson: 'Ecological approach to visual perception' (Houghton-Mifflin, Boston, 1979). 3. C. Thorpe and C.M. Friend: 'Modelling intelligent electronic consumer products', J. of Intelligent Mat. Syst. & Struct. 10(7) 552-557. 4. C. Thorpe: 'Smart consumer products - An approach to their design and evaluation'. PhD thesis, Cranfield University, UK, 2000. For more information contact: Clifford M. Friend, Humanware Group, Cranfleld University,Shrivenham, SwindonSN6 8LA, UK.TeI:+44 1793 785327. Email:
[email protected] Thispaper was presentedat the EuropeanWorkshop on Applications for Smart Structures in Engineering and Technologyin May 2002.
Radar absorbing materials for X- and Ku-band frequencies Samples consisting of an elastomeric matrix containing different kinds of active materials in particulate form were prepared for reflectivity measurements. The materials individually used in weight contents of 80% in polychloroprene matrix were: carbonyl-iron (CI) and doped ferrite powders. The microwave reflectivity levels were determined from the magnetic and dielectric properties of the elastomeric composites obtained from scattering data, by fitting the samples in a waveguide, for measurements in the frequency range from 8 to 16GHz. Better microwave absorption for X-band was obtained for CI while doped ferrite absorbed at higher frequencies (Ku-band). M.S Pinho, M.L. Gregori, R.C.R Nunes, B.G. Soares: European PolymerJournal38, (11) 23212327 (2002).
Polyfluorenes with dendron side chains for polymer LEDs The synthesis of a polyfuorene with polyphenylene dendrons as side chains was reported. It was shown that polymer light-emitting devices (PLEDs)from these materials possess very promising properties. In addition, it was also shown that the chemical stability and the shape persistence of Mullen-type dendrimers allows an effective shielding of the polyfluorene backbone at lower dendron generation numbers compared to Frechet-type ones. Alexander Pogantsch, Franz P Wenzl, Emil J.W. List, Gunther Leising, Andrew C. Grimsdale, Klaus Mullen, Advanced Materials 14 (15) 10611064 (5 August, 2002).
November 2002
almost 'love-like' feelings towards inanimate objects such as cars. [1] of information technology, offers the prospect of engineering systems which can sense their Cognitive aspects, on the other hand, arise local environment, interpret changes in this environment and respond appropriately. from individuals' response to their environment, Demonstrator projects exist world-wide exploring the range of possible applications for 'smart' including objects, and how from this perspective technologies in sectors ranging from aerospace and civil engineering to automobile and marine. the physical form of objects can 'afford' or 'force' A common feature of such programmes is their use of relatively sophisticated technologies, a particular behaviour.[2] examples including the use of fibre optic techniques for sensing and actuation based on Couched in these terms this again seems functional materials such as piezoceramics, electro- and magnetostrictives and shape-memory strange. However, one need only have 'pushed' a alloys. The use of such advanced technologies is symptomatic of the strong technology push door marked 'pull' to understand that the which has dominated the development of this field. physical form of an object as simple as a door handle can 'afford' a response (that is pushing) The novelty aspects of adaptive materials despite the door's 'obvious' mode of operation such as thermochromic materials and highly (communicated by the pull sign).[1] So how can the concept of 'smart' material viscoelastic plastics have also been exploited in There is no doubt that the development of products ranging from packaging and tee shirts systems enhance both aspects of a product? A major commercial issue in the design of 'smart' technologies have been technology to children's toys and mountain bikes. domestic products is differentiation, that is how The applications illustrated lie at almost pushed. However, as development of these to make a product 'stand out' amongst its systems has improved, there is an increasing need opposite ends of the 'smart' spectrum, the competitors. to match enabling technologies to the true former being examples of technology push into In a traditional commodity market such as the consumer goods sector and the latter requirements of a given application sector. consumer goods, this is usually done on price (the This has not only focussed on the appro- exploiting little more than the novelty of the lowest price!) but if one also understands the nature priateness of certain advanced technologies in materials, with no real integration into the true of user/object interactions, in particular emotional particular sectors - such as fibre optic sensing in design issues of the products themselves. interactions, these too can be used to differentiate. So how could a 'smart' design approach, the built environment, but also on the wider From a product design viewpoint underissue of whether 'smart' technology is truly a integrated with novel functional materials, create standing user/object interactions, such as cogcollection of technologies, or instead a new new and improved consumer goods? The key in sectors ranging from domestic ' nitive aspects, also enables one to design better paradigm for the design of products and systems. The latter is an important issue, since consumer goods to consumer healthcare consumer products with improved market recognition that products can be adaptive offers products is in the way 'smart' design can improve segmentation and high levels of user satisfaction. It is this interface between user/object new design options in a wider range of non- user/product interaction. For example, our homes are full of 'flawed' interaction, design and adaptive materials that conventional application sectors. Adopting 'smartness' as a design paradigm therefore creates products which we have problems using or points the way to new consumer products, but it is an area that is relatively unexplored and a new range of strong application pulls for the experience little pleasure in their use. 'Smart' design offers the potential of new unfamiliar to technologists. development of further 'smart' products, such as generations of products which are more intuitive 'smart' consumer goods. to use, create pleasure and meet different user needs.
Technology push moves to application pull
'Smart' consumer goods
The application of 'smart' technologies within the consumer goods market has as yet barely been explored. Perhaps best known is the development of a number of'smart' skis. These draw on many of the technology intensive solutions developed for aerospace and automobile applications. The aim being to create skis which adapt to ambient temperature - shape memory alloys adapting the stiffness of skis to various conditions such as soft snow and ice, or damping offvibration through the use of piezoelectric shunts.
@Smart MaterialsBulletin
User/object interaction Before considering the potential of 'smart' consumer products, it is perhaps useful to explore aspects of user/product interaction. Two of the most important are emotional and cognitive interactions. Emotional aspects arise from a product's 'behaviour' which emerges during user interaction, the product creating 'pleasure'. At first sight this seems a rather strange concept, but explains why many of us have
November2002
r
~,q
FEATURE appliances and is relatively easy to manufacture by injection moulding the kettle body with a thermochromic filler; a material familiar from colour change packaging, tee-shirts and other novelty goods. However, despite its deceptive simplicity, colour change must be carefully selected to create appropriate levels of pleasure and the correct affordances during use. This is important since from a thermochromic point of view not all colour changes are possible and selected materials and a product's 'language' must be carefully optimised together. A product based on these ideas is now commercially available in the Russell Hobbs' 'Thermocolodi' kettle (Figure 2), and anecdotal user response confirms this product's strong appeal and dynamic affordances - buy one and you'll experience it for yourselfl It is also a field which has only recently begun to be explored by ourselves for clients ranging from consumer healthcare to banking products and domestic consumer goods. For example, currently affordances and 'emotion' are created by designing a product's physical form. 'Smart' material technologies offer a sea-change in this design practice. [3] Moving from passive to active materials will create new types of affordance and enhance the emotional content of consumer goods.
Dynamic visual interfaces The concept of 'smart' consumer products is perhaps best illustrated with a case study. The most well known that we have worked on is the electric kettle. How can one use 'adaptive' materials to enhance the emotional content and affordances available in a kettle? This is well illustrated by our work on a thermochromic version, where active materials are used to create a dynamic visual change during use. One of our computer models of such a kettle is shown in Figure 1, where the body colour responds to the heating of its contents. It is difficult to communicate the effect of such a dynamic change in a static image, however our work has shown that the 'pleasure' associated with this kettle is strongly enhanced by such changes, clearly differentiating the product. New affordances are also created, correctly selected colour changes producing a strong metaphor for temperature and or safety and fill levels. This relatively simple example represents a break-through product in this family of
November2002
Physical dynamic interface Our work is not restricted only to visually dynamic products. Perhaps even greater levels of emotional response can be created using physically dynamic materials. Here we are exploring products in the consumer appliance and healthcare sectors. We have been investigating polymers and gels to create physically dynamic products which respond to the 'mood' of their user, gentle handling creating a 'cuddly' low stiffness response, compared to a stiffer response on rougher handling - all achieved through enhanced levels of strain-rate sensitivity. We have already begun to uniquely explore the user value of these physically dynamic products Typical user pleasure indices for a physically dynamic appliance, the female users developing 'relationships' with the product, and the males responding to pleasures associated with the
1000
80.0
700 i
o
s o o 6 ° ° ~ 1 ~ 400
•Smart
[ ] Non-smart
30.0
20.0
10.0 O0
'mind,' 'values' and 'senses' using quantitative techniques originally developed fbr the assessment of computer interfaces. This is enabling us to not only evaluate consumers' views on usability,,but to also deconstruct the more kmdamental reasons behind their 'pleasure'.[4] This is illustrated ill Figure 3, which shows both male and female consumers' preference for 'smart' humanware products. Figure 4 also shows how one can now differentiate the origins of this 'pleasure' between consumer groups, females finding pleasure in developing 'relationships' with the products, whilst males respond to pleasures associated with the 'mind,' 'values' and "senses'. Such quantitative tools enable us to carefully tune the behaviour of" these 'smart' products so that their 'pleasure' can be optimised for the widest range of consumers. However, there are also many products whose usability would be enhanced if they were not
80
8o x
°t
•
_
.
.
.
.
.
.
.
.
.
.
1
30
320
320 ~1o ~- o -lo -20
~- o -lO -20 Female
Male PLEASURES
I
IDEO
to do with values
!
PSYCHO
to do with the mind
I
soc~o
to do with relationships
PHYSIO
to do with the bodyand senses
SmartMaterialsBulletin @
~ESEARCH TREND c. optimised to an 'average' person but that 'one size adapted to all'. The 'smart' design approach can also contribute strongly here. For example, handles that adapt uniquely to their immediate user and which also uniquely adapt to all subsequent users. These could be applied to products ranging from kitchen goods and consumer healthcare to the automotive sector. Here again highly conformable elastic materials such as elastomers and polymer gels can play a central role. Such products offer significantly enhanced usability for the old, handicapped, young, left/right-handed, with the design concept being sufficiently generic to be applied in a wide range of products. The 'smart' structures concept is attractive and entirely transferable to the consumer goods
ResearchTrends Smart performance garments The difficulties facing manufacturers of survival clothing is considered, including the need to define worst case conditions in which garments may need to afford protection. Decathlon, with a turnover of £2bn has worked closely with Leeds University to define the most important performance parameters for survival clothing. Key factors in comfort are ambient humidity and moisture management, not temperature. The design and patenting of an ultra-low spacer fabric claimed to be superior to current fleece fabrics is outlined. Detailed design of performance clothing is as important as materials used, as is subsequent testing to confirm design goals have been reached. High technology (or smart textiles in both passive form (achieved by textile design), or active form (where energy input is needed) are detailed. I Holme: Textile Horizons May/June 7-8 (2002) Survival 2002.
Shape change from AgnOxHy silver cluster on graphite induced by their chemical composition The deposition of AgnOxHy clusters onto a graphite surface, maintained at room temperature, as a function of the cluster chemical composition has been investigated. The incident clusters were produced by a gasaggregation silver cluster source when adding 0 2 and H 2 0 molecules in the carrier gas, and monitored by a time of flight mass spectrometer. Samples were imaged by electron microscopy.
Smart Materials Bulletin
market, providing that simpler technological solutions are sought which best match the requirements of the sector. The adaptivity of 'smart' products offers a new design paradigm enhancing user/product interaction through much greater emotional engagement and the use of dynamic visual and physical affordances.
Breakthrough products We have only just begun to explore the potential of 'smart' consumer products, which offer the potential of breakthrough products in a wide range of consumer goods markets. Successful development of 'smart' consumer products depends on a clear understanding of product design, user/object interaction and deep knowledge of appropriate adaptive technologies.
Results show that cluster diffusion and agglomeration on the surface as well as the resulting island morphology strongly depend on the cluster chemical composition. If the deposition of pure silver clusters leads to nano-fractal islands, a few of oxide/hydroxide molecules incorporated as impurities into the incident clusters prior to their deposition induce a post fractal island fragmentation, keeping constant the fractal dimension.Deposition of totally oxidised/hydroxided clusters induces drastic change in island morphology with a decrease of the cluster diffusion on graphite. In this case a dense nano-phase material with narrow size particle distribution in chain-like structure is obtained. C. Brdchignac, Ph. Cahuzac, E Carlier, N. Kdba'ili, J. Le Roux, A. Masson: Surface Science 518 (3) 192-200 (20 October, 2002).
Photoemission effects from Au nano clusters on TiO2 Valence level and shallow core states of Au nanoclusters on TiO2(1 1 0) have been studied by synchrotron excited photoemission. The shift to high binding energy and broadening of the Au 4f peaks with decreasing Au surface coverage can be understood in terms of decreasing cluster size and the associated effects of charge on the cluster in the final state. Shifts in the photo emission onset are more pronounced than the core level shifts and show strong dependence on the degree of reduction of the TiO2(1 1 0) substrate. This suggests that photoemission onset is influenced by initial state effect involving charge transfer from defect into cluster states. A. Howard, D. N. S. Clark, C. E. J. Mitchell, R. G. Egdell, V. R. Dhanakb: SurfaceScience518 (3) 210-224 (20 October 2002).
References 1. D.A. Norman: 'Psychology of everyday things' (Basic Books, New York, 1998). 2. J.J. Gibson: 'Ecological approach to visual perception' (Houghton-Mifflin, Boston, 1979). 3. C. Thorpe and C.M. Friend: 'Modelling intelligent electronic consumer products', J. of Intelligent Mat. Syst. & Struct. 10(7) 552-557. 4. C. Thorpe: 'Smart consumer products - An approach to their design and evaluation'. PhD thesis, Cranfield University, UK, 2000. For more information contact: Clifford M. Friend, Humanware Group, Cranfleld University,Shrivenham, SwindonSN6 8LA, UK.TeI:+44 1793 785327. Email:
[email protected] Thispaper was presentedat the EuropeanWorkshop on Applications for Smart Structures in Engineering and Technologyin May 2002.
Radar absorbing materials for X- and Ku-band frequencies Samples consisting of an elastomeric matrix containing different kinds of active materials in particulate form were prepared for reflectivity measurements. The materials individually used in weight contents of 80% in polychloroprene matrix were: carbonyl-iron (CI) and doped ferrite powders. The microwave reflectivity levels were determined from the magnetic and dielectric properties of the elastomeric composites obtained from scattering data, by fitting the samples in a waveguide, for measurements in the frequency range from 8 to 16GHz. Better microwave absorption for X-band was obtained for CI while doped ferrite absorbed at higher frequencies (Ku-band). M.S Pinho, M.L. Gregori, R.C.R Nunes, B.G. Soares: European PolymerJournal38, (11) 23212327 (2002).
Polyfluorenes with dendron side chains for polymer LEDs The synthesis of a polyfuorene with polyphenylene dendrons as side chains was reported. It was shown that polymer light-emitting devices (PLEDs)from these materials possess very promising properties. In addition, it was also shown that the chemical stability and the shape persistence of Mullen-type dendrimers allows an effective shielding of the polyfluorene backbone at lower dendron generation numbers compared to Frechet-type ones. Alexander Pogantsch, Franz P Wenzl, Emil J.W. List, Gunther Leising, Andrew C. Grimsdale, Klaus Mullen, Advanced Materials 14 (15) 10611064 (5 August, 2002).
November 2002