Stretchable electronics is emerging as a promising new technology for next-generation wearable devices, according to a review published in Science and Technology of Advanced Materials.
The technology has many possible applications for healthcare, energy and the military. But there are several challenges involved in finding suitable materials and manufacturing methods. The biggest challenge for making stretchable electronics is that each component must endure being compressed, twisted and applied to uneven surfaces while maintaining its performance, according to the review author Wei Wu – materials scientist at Wuhan University, China.
A number of new stretchable electronic components are under development. For instance, low-cost stretchable conductors and electrodes are being made from silver nanowires and graphene. In another instance, the urgent technical need for stretchable energy conversion and storage devices, such as batteries, has given rise to zinc-based batteries as a promising candidate. But if this proves unsuccessful, an alternative is stretchable nanogenerators, which can produce electricity from various freely available vibrations, such as wind or human body movements.
By integrating multiple stretchable components, such as temperature, pressure and electrochemical sensors, it is possible to create a material resembling human skin that could use signals from sweat, tears or saliva for real-time, non-invasive healthcare monitoring, as well as for smart prosthetics or robots with enhanced sense capabilities.
Currently there are two main strategies for manufacturing stretchable electronics. The first is to use intrinsically stretchable materials, such as rubber, which can endure large deformations. However, these materials have limitations, such as high electrical resistance.
The second method is to make non-flexible materials stretchable using innovative design. For example, brittle semiconductor materials like silicon can be grown on a pre-stretched surface and then allowed to compress, creating buckling waves. One could also link ‘islands’ of rigid conductive materials together using flexible interconnections, such as soft or liquid metals.
Additionally, Origami-inspired folding techniques can be used to make foldable electronic devices. In the future, stretchable electronics may be enhanced with new capabilities, such as wireless communication, self-charging or even self-healing.
The next step after laboratory tests is to bring stretchable electronic devices to market. This requires cheaper materials and faster, scalable manufacturing methods, concludes the review author.
For more information, contact: