Smart Materials 1 – Definition
Last night I was at the smart materials event at the Dana Center in Londons Science Museum where a number of interesting materials that could be potentially applied to interactive architecture. I personally didn’t find anything that was mindblowingly new but it was good to talk to some of the people in this industry and discuss the future uses of these materials.
An obvious way to start an overview of Smart Materials should be to provide a definition of Smart Materials. However, beyond the completely accurate but not too useful, “a material that displays smart behaviour” that is easier said than accomplished. To define a Smart Material we really need to understand what is meant by Smart behaviour and then, by means of some examples, to develop our definition.
Smart behaviour occurs when a material can sense some stimulus from its environment and react to it in a useful, reliable, reproducible and usually reversible manner. A really Smart material will use its reaction to the external stimulus to initiate or actuate an active response, e.g. with an active control system. Whilst this is perhaps a more useful definition examples from familiar items would help at this point.
There are some materials that are designed to change their colour at a particular temperature. They find uses in bath plugs that show when the bath water is too hot, children’s feeding spoons and coffee or tea mugs. Gromit’s nose on the PG Tips mug is a very recent example. Technically this is described as “thermochromic” behaviour where a thermal stimulus causes a useful optical response.
Smart behaviour is therefore the reaction of a material to some change in its environment, no material can be Smart in isolation, it must be a part of a structure or system such as the bath plug, the spoon or the coffee mug.
Another interesting heat responsive material is Oricalco
This men’s shirt by Corpo Nova is woven with titanium, which allows the fabric to react to temperature shifts. The shirt holds its wrinkles when bunched up, and then instantly relaxes when exposed to a current of hot air (as from an electric hair dryer). The shirt can thus be ‘ironed’ while its user wears it.
Here’s a project at MIT using Smart Materials I really love called Puddlejumper
Puddlejumper is a luminescent raincoat that glows in the rain. Hand-silkscreened electroluminescent lamps on the front of the jacket are wired to interior electronics and conductive water sensors on the back and left sleeve. When water hits one of the sensors, the corresponding lamp lights up, creating a flickering pattern of illumination that mirrors the rhythm of rainfall.
more on Smart Materials soon to come…
TagsDevices New Materials
Electroluminescent lamps would be a great solution for night-time safety equoment for cyclists.
Problem is that their more expensive than LEDs for example. Whats nice about the material is that it can be sewn into fabrics and releases an equal glow all the way along its length
You might find this article on the colour technology used behind ‘zubbles’ — colour bubbles interesting:
Interesting project, we like so much all about MIT projects.
We’re working, now, in our last project with sensors and textile, too 😀 😛
See u soon. Best Regards,
rodri_DJ & ivan_VJ
While piezoelectric energy harvesting typically focuses on converting mechanical into electrical energy on the basis of the linear reversible piezoelectric effect, the potential of exploiting the non-linear ferroelectric effect is investigated theoretically in this paper. Due to its dissipative nature, domain switching, on the one hand, is basically avoided in order to prevent mechanical energy from being converted into heat. However, the electrical output, on the other hand, is augmented due to the increased change of electric displacement. In view of these conflicting issues, one main objective in ferroelectric energy harvesting thus is to identify mechanical and electrical process parameters providing appropriate figures of merit. Being an efficient approach to numerically simulate multiphysical polycrystalline material behavior, the so-called condensed method is taken as a basis for the investigation and finally optimization of controllable parameters of ferroelectric energy harvesting cycles. A first idea of a technical implementation taken from literature is considered as cycle of reference, constituting the starting point of the present study, being focused on material aspects rather than on harvesting devices. Different quality assessing parameters are introduced, taking into account general aspects of harvesting efficiency as well as the ratio of irreversible switching-related to reversible piezoelectric contributions. Residual stresses are likewise predicted to give an idea of reliability and the risk of fracture. Two types of cycles and associated optimal process parameters are finally presented.