Super-thin, flexible electronics

Researchers at the Swiss Federal Institute of Technology have found a way to make super-thin, flexible electronics which can be applied to almost any surface...

In this paper, published in Nature Communications, the thin film transistors are machined onto a film of a material called parylene only 1 micrometre - just a thousandth of a millimetre - thick.

To hold the film in place while this was being done, they attached it to a piece of silicon. The clever bit is that the glue they used to attach the film to the silicon is soluble, so once they have made the thin film transistor, they can pop it in some water, and the silicon wafer falls off as the glue dissolves, leaving just the film floating on the water.

Parylene was chosen because it is bio-compatible, and can be attached to a wide variety of materials, from textiles and implantable devices to plant leaves and human skin, giving a huge range of possible applications.

Both transparent and not transparent versions of the transistors were made, widening their possible uses even further.  These devices could withstand bending over human hairs, and even putting them on a piece of foil before repeatedly being crumpled and flattened.

Both the transparent and non-transparent versions worked fine when bent over the hair, and while only the non-transparent one survived the foil test, it was a pretty extreme challenge, so still a win for the scientists overall!

Because the membrane is so thin, light, and biocompatible, there are a huge number of possible uses for the technology.

One idea being explored is to use the devices to detect strain to a plastic contact lens that could be used to monitor eye diseases like glaucoma.