Biodegradable electronics in manufacturing

It may shortly be possible to compost surplus electronics in the same way as you do with fruit and vegetable waste. This is thanks to the arrival of printed electronics made from natural and compostable materials.

Researchers at the Young Investigator Network at the German Karlsruhe Institute for Technology (KIT) are currently developing printed electronics using natural, compostable materials and inks. This could eventually lead to the reduction of millions of tons of electronic waste around the world each year that is simply thrown away.

For example, using this technology would make it possible to produce compostable stickers with electronic, printed traffic lights indicating the shelf life of a product, or plasters with built-in sensors for monitoring the healing process.

Foils and inks

Replacing silicon, heavy metals and other environmentally harmful elements, the researchers are working with biologically degradable materials including starch, chitin and cellulose, as well as semiconductors and inks made from plant extracts and insulators made from hard gelatine (as already used in hard medicine capsules).

The advantages presented by these organic materials include pliability, low prices and the ability to process them on kilometres of printing foil. The electronic components are printed on compostable foil, in the same way as letters printed on paper. The actual function depends on the ink used: instead of colour particles, conductive particles, semiconductors and nonconducting (insulating) materials are used which are dissolved in the ink. Once applied, the fluid solution dries up and the remaining layer forms the corresponding component. 

Compatibility

The research is aimed at developing biodegradable, foil materials that can be used with existing printing equipment. This way organic electronics manufacturers can switch over to environmentally-friendly materials without having to adapt all their printing equipment. The biologically degradable versions may not last as long as their inorganic counterparts, but they can easily exceed the lifespan required for disposable electronics.

A significant breakthrough in fully biologically degradable electronics will take place with the development of inks for the printed links that have all the ecological and conductive properties, and just as importantly, do not cause blockages in printers and can form enclosed, fluid and homogeneous films that do not drip. This is the current challenge being focused on by the research team.

The scientists hope to have compostable, organic components ready for the suppliers and retail outlets within three years.