E-waste is a growing problem, so if an electronic component can't be reused or recycled, it should at least be biodegradable. That's where an experimental new electronic display comes in, as it can be composted when no longer needed.
Created by scientists at Germany's Karlsruhe Institute of Technology (KIT), the device is a type of electrochromic display. It utilizes an organic polymer known as PEDOT:PSS, in which the amount of light absorption changes as voltage is applied – as a result, individual segments of the display change between almost-clear and opaque states.
That polymer is deposited on a cellulose di-acetate substrate and sealed in an electrolyte gelatine, making the display both flexible and adhesive. The electrical current is applied via gold electrodes. And like other electrochromic displays, this one can be inexpensively produced using an inkjet printer.
The printing process could reportedly be easily scaled up for commercial production, yet it also allows for the production of small runs of specialized displays in custom shapes or sizes.
According to the researchers, the technology will likely find use in short-lifecycle applications. These could include disposable skin-worn sensors that monitor patients' conditions, or food packaging that indicates if the food has spoiled.
"As far as we know, this is the first demonstration of a biodegradable display produced by inkjet printing," says Gerardo Hernandez-Sosa, head of the Printed Electronics Group at KIT's Light Technology Institute. "It will pave the way to sustainable innovations for other electronic components and to the production of eco-friendlier electronics."
The display is described in a paper that was recently published in the Journal of Materials Chemistry.