Foto: Sam Rentmeester

Photo: Sam Rentmeester

Within 20 years, functional polymers will be the smartest material that exists, says Dr Kaspar Janssen (Industrial Design Engineering).

‘Feel free to call polymers plastic, but I prefer to focus on material systems. Functional polymers are smart materials that are capable of interacting with their surroundings and with people. There are three types. The material structure can be influenced on an atomic scale to achieve such properties as biodegradability. To date, considerable effort has been invested in this area through the addition of starch, which breaks down under the influence of moisture and warmth. In addition, plastics can be made functional on a molecular scale. One example involves the addition of piezo crystals, so an electrical current can run through them. Finally, the third possibility is to design a material on the micro scale through the application of a texture to the surface. For example, micro-hairs can be used to make a product water-resistant. We refer to this as the lotus effect.

Although these sorts of things are now possible only in the laboratory, I think that in the future it will be very easy to manufacture much larger surfaces. Another promising production method is 3D printing. The advantage of 3D printing is that it allows you greater control over the material. Plastics always expand more than metal or ceramic. With 3D printing, you can determine the expansion coefficient with considerable precision. This also makes it possible to produce materials in which multiple functionalities can be integrated. Examples include transparent plastic with light channels, with the intensity of the light changing when it is touched.

I think that this type of integration of materials into electronics will become the most important field of research in the future. I can envision products – on your body, in your clothing, in your car or in your office – that take a wide range of continuous measurements and that remain in contact with each other: the ‘internet of things’. For example, imagine clothing that could provide active cooling in a warm environment, buildings with smart coatings on the windows that selectively allow sunlight, or a remote control that changes colour when it needs to be charged. In our department, we are working to develop a vision for the future in this area.

One challenge will be to resolve the problem of energy in electronics, because it is very inconvenient to be changing batteries all the time. With ‘energy harvesting’, you could store the energy of every footstep in the sole of your shoe and use it to charge a battery. In addition, electronics will have to become more flexible. If you want stretchable chips that can be placed alongside each other in a piece of rubber, it is important for the electrical connections not to break. I’m convinced that smart tricks will be developed for this as well.’

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