Researchers at the Max Planck Institute of Colloids and Interfaces in Potsdam-Golm, Germany have developed a simpler and more cost-efficient means of creating microchips for electronics applications using paper and a conventional inkjet printer.
The use of flexible, cost-efficient microchips as a replacement for silicon chips, which are more expensive and difficult to make, is becoming increasingly popular in electronics applications. As a replacement for the silicon in the new microchips, plastic has long been used as the carrier, and, in some cases, polymers and other organic molecules are used as conductive components.
However, these materials need to meet many requirements and are, without exception, sensitive to heat.
“Their processing cannot be integrated into the usual production of electronics, because temperatures in production can reach over 400 degrees Celsius,” Cristina Giordano, the leader of a working group at the Max Planck Institute of Colloids and Interfaces, said.
Using the inkjet printer, Giordano and her colleagues turned a sheet of paper into conductive graphite by printing a catalyst of iron nitrate on the paper and heating it. Carbon electronics, which Giordano and her colleagues are able to create from paper using their new method, can withstand temperatures of up to 800°C during production in an oxygen-free environment. The research team’s new material is also light, inexpensive and can also be processed very easily.
In another experiment, the research team demonstrated how three-dimensional, conductive structures can be created with their new method by folding a sheet of paper into an origami crane, immersing it in the catalyst and baking it into graphite.
“The three-dimensional form was completely retained, but consisted entirely of conductive carbon after the process,” Stefan Glatzel said.