Foldable and Flexible Microchips Soon a Reality

According to researchers at the University of Illinois at Urbana-Champaign, you can forget the notion that silicon - the stuff of your window glass and computer chips - can't be folded and stretched. A multi-institutional team led by Dr. John Rogers released their findings via the journal Science, that appears in the March 27 edition of Science Express online.

"The notion that silicon cannot be used in such applications because it is intrinsically brittle and rigid has been tossed out the window," said Rogers in a press release from the University of Illinois. Rogers is a Founder Professor of Materials Science and Engineering at Illinois.

Building on research released in 2005, the teams from Illinois, Northwestern University (Evanston, IL), and the Institute of High Performance Computing in Singapore have created a foldable, stretchable chip that remains fully functional even while and after being deformed. In that earlier research, Rogers' team developed a one-dimensional, stretchable form of single-crystal silicon with wave-like geometries.

"We've gone way beyond just isolated material elements and individual devices to complete, fully integrated circuits in a manner that is applicable to systems with nearly arbitrary levels of complexity," said Rogers. "We're opening an engineering design space for electronics and optoelectronics that goes well beyond what planar configurations on semiconductor wafers can offer."

In other words - microchips will not have to just be flat chunks of silicon with transistors on them any more, and can instead be manufactured with the intent of them being folded around an object, and still working as desired without any degradation in performance.

The new method of dry substrate fabrication has many potential uses in any system that requires flexibility. Talk has already started on systems for biomedical monitoring (wearable monitors) devices, to wrap-around telemetry systems for aircraft wings. Designers making use of the new fabrication technique would be able to design and manufacture chips made to fit the shape of an object, instead of the other way around. Imagine a flower pot - that is also a computer or stereo system.

Their demonstration device used the new substrate, incorporation already tested microdevices such as transistors, oscillators, logic gates and amplifiers. The finished device functioned as predicted, even after being folded and stretched.

Work was funded by the National Science Foundation and the U.S. Department of Energy. Co-authors include Dae-Hyeong Kim, Jong-Hyun Ahn, Won Mook Choi, Hoon-Sik Kim, Tae-Ho Kim, Jizhou Song, Yonggang Y. Huang, Zhuangjian Liu, and Chun Lu.