Stretchable silicon could be next wave in electronics

December 15, 2005

The next wave in electronics could be wavy electronics.

Researchers at the University of Illinois at Urbana-Champaign have developed a fully stretchable form of single-crystal silicon with micron-sized, wave-like geometries that can be used to build high-performance electronic devices on rubber substrates.

"Stretchable silicon offers different capabilities than can be achieved with standard silicon chips," said John Rogers, a professor of materials science and engineering and co-author of a paper to appear in the journal Science, as part of the Science Express Web site, on Dec 15.

Functional, stretchable and bendable electronics could be used in applications such as sensors and drive electronics for integration into artificial muscles or biological tissues, structural monitors wrapped around aircraft wings, and conformable skins for integrated robotic sensors, said Rogers, who is also a Founder Professor of Engineering, a researcher at the Beckman Institute for Advanced Science and Technology and a member of the Frederick Seitz Materials Research Laboratory.

To create their stretchable silicon, the researchers begin by fabricating devices in the geometry of ultrathin ribbons on a silicon wafer using procedures similar to those used in conventional electronics. Then they use specialized etching techniques to undercut the devices. The resulting ribbons of silicon are about 100 nanometers thick -- 1,000 times smaller than the diameter of a human hair.

In the next step, a flat rubber substrate is stretched and placed on top of the ribbons. Peeling the rubber away lifts the ribbons off the wafer and leaves them adhered to the rubber surface. Releasing the stress in the rubber causes the silicon ribbons and the rubber to buckle into a series of well-defined waves that resemble an accordion.

"The resulting system of wavy integrated device elements on rubber represents a new form of stretchable, high-performance electronics," said Young Huang, the Shao Lee Soo Professor of Mechanical and Industrial Engineering. "The amplitude and frequency of the waves change, in a physical mechanism similar to an accordion bellows, as the system is stretched or compressed."

As a proof of concept, the researchers fabricated wavy diodes and transistors and compared their performance with traditional devices. Not only did the wavy devices perform as well as the rigid devices, they could be repeatedly stretched and compressed without damage, and without significantly altering their electrical properties.

"These stretchable silicon diodes and transistors represent only two of the many classes of wavy electronic devices that can be formed," Rogers said. "In addition to individual devices, complete circuit sheets can also be structured into wavy geometries to enable stretchability."

Besides the unique mechanical characteristics of wavy devices, the coupling of strain to electronic and optical properties might provide opportunities to design device structures that exploit mechanically tunable, periodic variations in strain to achieve unusual responses.

In addition to Rogers and Huang, co-authors of the paper were postdoctoral researcher Dahl-Young Khang and research scientist Hanqing Jiang. The Defense Advanced Research Projects Agency and the U.S. Department of Energy funded the work.
-end-
Editor's note: To reach John Rogers, call 217-244-4979; e-mail: jrogers@uiuc.edu. To reach Yonggang Huang, call 217-265-5072; e-mail: huang9@uiuc.edu.

University of Illinois at Urbana-Champaign

Related Engineering Articles from Brightsurf:

Re-engineering antibodies for COVID-19
Catholic University of America researcher uses 'in silico' analysis to fast-track passive immunity

Next frontier in bacterial engineering
A new technique overcomes a serious hurdle in the field of bacterial design and engineering.

COVID-19 and the role of tissue engineering
Tissue engineering has a unique set of tools and technologies for developing preventive strategies, diagnostics, and treatments that can play an important role during the ongoing COVID-19 pandemic.

Engineering the meniscus
Damage to the meniscus is common, but there remains an unmet need for improved restorative therapies that can overcome poor healing in the avascular regions.

Artificially engineering the intestine
Short bowel syndrome is a debilitating condition with few treatment options, and these treatments have limited efficacy.

Reverse engineering the fireworks of life
An interdisciplinary team of Princeton researchers has successfully reverse engineered the components and sequence of events that lead to microtubule branching.

New method for engineering metabolic pathways
Two approaches provide a faster way to create enzymes and analyze their reactions, leading to the design of more complex molecules.

Engineering for high-speed devices
A research team from the University of Delaware has developed cutting-edge technology for photonics devices that could enable faster communications between phones and computers.

Breakthrough in blood vessel engineering
Growing functional blood vessel networks is no easy task. Previously, other groups have made networks that span millimeters in size.

Next-gen batteries possible with new engineering approach
Dramatically longer-lasting, faster-charging and safer lithium metal batteries may be possible, according to Penn State research, recently published in Nature Energy.

Read More: Engineering News and Engineering Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.