I was pleasantly surprised this morning when I opened the Stanford electronic newsletter. One of my colleagues, Zhenan Bao from Chemical Engineering, is developing an ultra-thin and stretchy material that can sense touch, detect chemicals and power itself with ultrathin and stretchable solar cells.
The skinny solar cells have a wavy stretchable structure, a bit like an accordion. Liquid metal electrodes are used that conform to the variable surface. It is not hard to imagine using these cells on fabrics. Fancy a solar cell suit?
The first solar PV cells were made of crystalline silicon. Such cells are relatively thick and stiff. Second generation PV cells are thin film cells, like the Cadmium-Tellerium cells produced by the US based company FirstSolar. A big advantage of thin film cells is that they are flexible and can be fitted to curved surfaces. To not only have flexible materials but also stretchable materials, like the solar skin developed by Bao and her colleagues, is very attractive. It can be fitted to moving parts without fear of cracking, wrinkling or breaking. The solar cells work also in stretched state.
I am not sure what the power density is of these solar cells, nor how much the power delivery is cut in stretched state. But, this is of course only a first prototype. My guess is that we’ll see very rapid developments in this area. The applications are just too attractive not to draw large investors.
We hope to organize an interview with Bao and ask her more about the underlying technology.
This is one of these research outcomes that makes science fiction science non-fiction. I love it.