A team of researchers from the State University of New York at Binghamton created a prototype circuit board made of a sheet of paper with fully integrated electrical components that can be burned or left to degrade after use.

Most small electronic devices contain circuit boards that are made from glass fibres, resins and metal wiring. These boards are not easy to recycle and are relatively bulky.

Paper-based circuit boards are not new per se. However, current options require specialized paper or have traditional metal circuitry components. In the new design, however, all electric components are fully integrated into the sheet.

The team designed a paper-based amplifier-type circuit that incorporated resistors, capacitors and a transistor. They first used wax to print channels onto a sheet of paper in a simple pattern. After melting the wax so that it soaked into the paper, the team printed semi-conductive and conductive inks, which soaked into the areas not blocked by wax. Then, the researchers screen-printed additional conductive metal components and casted a gel-based electrolyte onto the sheet.

The final circuit was very flexible and thin, just like paper, even after adding the components. To demonstrate the degradability of the circuit, the team showed that the entire unit quickly burned to ashes after being lit on fire.

Photo: American Chemical Society via EurekAlert