Electronics can do the twist

Electronics can now shape into any complex deformation, including twisting.

“Pop-up” technology creates circuits that can twist and shape into different forms. This technology could see use in places where flat, unbending electronics would fail, like on the human body, said Yonggang Huang, Joseph Cummings Professor of Civil and Environmental Engineering and Mechanical Engineering at Northwestern University’s McCormick School of Engineering and Applied Science, and John Rogers, the Flory-Founder Chair Professor of Materials Science and Engineering at the University of Illinois at Urbana-Champaign.

Electronic components historically have been flat and unbendable because silicon, the principal component of all electronics, is brittle and inflexible. Any significant bending or stretching renders an electronic device useless.

Huang and Rogers developed a method to fabricate stretchable electronics that increases the stretching range (as much as 140%) and allows the user to subject circuits to extreme twisting. This emerging technology promises new flexible sensors, transmitters, new photovoltaic and microfluidic devices, and other applications for medical and athletic use.

The partnership, where Huang focuses on theory and Rogers focuses on experiments, has been fruitful for the past several years. Back in 2005, they developed a one-dimensional, stretchable form of single-crystal silicon they could stretch in one direction without altering its electrical properties. Earlier this year, they made stretchable integrated circuits. Next, the researchers developed a new kind of technology that allowed circuits to go on a curved surface. That technology used an array of circuit elements approximately 100 micrometers square connected by metal “pop-up bridges.”

The circuit elements were so small that when placed on a curved surface, they did not bend—similar to how buildings do not bend on the curved Earth. The system worked because the metal wire allowed the elements to pop up when they bent or stretched it.

Huang and Rogers took their pop-up bridges and made them into an “S” shape, which, in addition to bending and stretching, have enough give they can twist as well.

“For a lot of applications related to the human body, like placing a sensor on the body, an electronic device needs not only to bend and stretch but also to twist,” Huang said. “So we improved our pop-up technology to accommodate this. Now it can accommodate any deformation.”

Huang and Rogers now are focusing their research on another important application of this technology—solar panels. They designed a new process of creating very thin silicon solar cells that can combine in flexible and transparent arrays.

For related information, go to www.isa.org/manufacturing_automation.

Tags: electonics, news, technology

This entry was posted on Wednesday, December 10th, 2008 at 2:49 pm and is filed under Technology News. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.