Flexible circuitry is a big upcoming trend in electronics, but there remain a few challenges to overcome before it can really take off. Now Polyera, a US company that makes specialist chemicals for flexible electronic devices, may have done that by inventing a new type of ink that could make true print-out flexible semiconductor integrated circuitry possible.
Existing “semiconductor inks” that researchers have created have been capable only of behaving as p-type semiconductors. P-type semiconductors, in the traditional solid semiconductors world, are doped materials where the average electron numbers are reduced, creating “holes” that act as positive charge carriers. You need the opposite n-type materials (n for negative) which have an abundance of electrons (carrying negative charge) to make anything electronically interesting such as a transistor–typically formed by layering some n-type material between two p-type blocks, or vice-versa.
Polyera’s research has now yielded an n-type ink-like semiconductor. Antonio Facchetti, CTO of the company, created the new material using a technique borrowed from the molecular modelling techniques used by the big pharmaceuticals to discover new drugs–essentially by searching for a molecule that’s the right shape to solve a particular problem. Polyera’s new material, sold under the ActivInk brand, has good electron transport characteristics, making it a good n-type material, is apparently very easy to manufacture and can be dissolved in water to create an ink.
The company is suggesting that this will open the gates for a new printed electronics revolution: by loading p- and n-type “inks” along with other conductive ink into an inkjet-like printer, it should be possible to rapidly, easily, and cheaply print-out fairly complex circuitry onto thin plastic sheets or possibly paper. One immediately obvious product this could create is more ubiquitous RFID tags, which could even be printed out directly onto a products surface.
While RFID sounds all very neat, I’m waiting for someone to combine this innovation with e-reader technology and create temporary moving-display tattoos–with the print-out tech there’d simply be no pain. Imagine digitally-programmable wallpaper patterns, and you see how big this technology could get.