Gutenberg’s movable type revolutionized the printing process, but it was still a batch-mode production. Individual sheets of paper were placed in the press one at a time, then printed. Eventually, roll-to-roll printing presses took over, printing pages much faster and at lower cost thanks to more efficient processing. When it comes to complex integrated circuits (ICs) such as computer processors or memory chips, we’re still stuck in the Gutenberg era; individual silicon wafers are processed one at a time.
A new process developed at the Korea Advanced Institute of Science and Technology (KAIST) and Korea Institute of Machinery and Materials (KIMM) may change all this. Scientists there have developed a process that allows them to “print” ICs onto flexible substrates using a continuous roll-to-roll process. The system starts with traditional silicon wafers as a substrate for the ICs, but the silicon is then dissolved away leaving just the electronic component. These are placed on a carrier, transferred a roller, which then deposits them on a conductive plastic film.
The researchers made memory circuits as their experimental product, and found that the devices continued to work in spite of repeated bending. This important development could open the door to much more sophisticated flexible devices, including computers that can be worn on a person’s skin. Wearable sensors could be made smarter and more capable, and could even incorporate displays using this technique.