Navigation Links
Foldable and stretchable, silicon circuits conform to many shapes

CHAMPAIGN, Ill. Scientists have developed a new form of stretchable silicon integrated circuit that can wrap around complex shapes such as spheres, body parts and aircraft wings, and can operate during stretching, compressing, folding and other types of extreme mechanical deformations, without a reduction in electrical performance.

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

Through carefully optimized mechanical layouts and structural configurations, we can use silicon in integrated circuits that are fully foldable and stretchable, said Rogers, who is a corresponding author of a paper accepted for publication in the journal Science, and posted on its Science Express Web site.

The new designs and fabrication strategies could produce wearable systems for personal health monitoring and therapeutics, or systems that wrap around mechanical parts such as aircraft wings and fuselages to monitor structural properties.

In December 2005, Rogers and his U. of I. research group reported the development of a one-dimensional, stretchable form of single-crystal silicon with micron-sized, wave-like geometries. That configuration allows reversible stretching in one direction without significantly altering the electrical properties, but only at the level of individual material elements and devices.

Now, Rogers and collaborators at the U. of I., Northwestern University, and the Institute of High Performance Computing in Singapore report an extension of this basic wavy concept to two dimensions, and at a much more sophisticated level to yield fully functional integrated circuit systems.

Weve 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, who also is a researcher at the Beckman Institute and at the universitys Frederick Seitz Materials Research Laboratory.

The wavy concept now incorporates optimized mechanical designs and diverse sets of materials, all integrated together in systems that involve spatially varying thicknesses and material types, Rogers said. The overall buckling process yields wavy shapes that vary from place to place on the integrated circuit, in a complex but theoretically predictable fashion.

Achieving high degrees of mechanical flexibility, or foldability, is important to sustaining the wavy shapes, Rogers said. The more robust the circuits are under bending, the more easily they will adopt the wavy shapes which, in turn, allow overall system stretchability. For this purpose, we use ultrathin circuit sheets designed to locate the most fragile materials in a neutral plane that minimizes their exposure to mechanical strains during bending.

To create their fully stretchable integrated circuits, the researchers begin by applying a sacrificial layer of polymer to a rigid carrier substrate. On top of the sacrificial layer they deposit a very thin plastic coating, which will support the integrated circuit. The circuit components are then crafted using conventional techniques for planar device fabrication, along with printing methods for integrating aligned arrays of nanoribbons of single-crystal silicon as the semiconductor. The combined thickness of the circuit elements and the plastic coating is about 50 times smaller than the diameter of a human hair.

Next, the sacrificial polymer layer is washed away, and the plastic coating and integrated circuit are bonded to a piece of prestrained silicone rubber. Lastly, the strain is relieved, and as the rubber springs back to its initial shape, it applies compressive stresses to the circuit sheet. Those stresses spontaneously lead to a complex pattern of buckling, to create a geometry that then allows the circuit to be folded, or stretched, in different directions to conform to a variety of complex shapes or to accommodate mechanical deformations during use.

The researchers constructed integrated circuits consisting of transistors, oscillators, logic gates and amplifiers. The circuits exhibited extreme levels of bendability and stretchability, with electronic properties comparable to those of similar circuits built on conventional silicon wafers.

The new design and construction strategies represent general and scalable routes to high-performance, foldable and stretchable electronic devices that can incorporate established, inorganic electronic materials whose fragile, brittle mechanical properties would otherwise preclude their use, the researchers report.

Were opening an engineering design space for electronics and optoelectronics that goes well beyond what planar configurations on semiconductor wafers can offer, Rogers said.


Contact: James E. Kloeppel
University of Illinois at Urbana-Champaign

Related biology technology :

1. UM physicists show electrons can travel over 100 times faster in graphene than in silicon
2. UCT Specialties (Formerly Petrarch) Announces the Release of Their New Product Guides for Silanes, Silicones, Platinum Catalyst and Glass Coatings
3. UDs Appelbaum wins NSF Career Award for research on silicon spintronics
4. Move over, silicon: Advances pave way for powerful carbon-based electronics
5. Job-related stress: NIST demonstrates fatigue effects in silicon
6. Align Technology, Inc. Ranked 23rd in Deloittes Technology Fast 50 Program for Silicon Valley Scientific & Medical Equipment, and Bio-Technology Companies
7. Worlds most complex silicon phased-array chip developed at UC-San Diego
8. Nanotube forests grown on silicon chips for future computers, electronics
9. FDA and Conformia Deliver Joint Presentation to Annual Regulatory and Compliance Symposium at Harvard
10. ConforMIS Moves Headquarters to Expanded Facilities in Burlington, MA
11. Sol-gel inks produce complex shapes with nanoscale features
Post Your Comments:
(Date:11/25/2015)... , November 25, 2015 ... Report is a professional and in-depth study on ...      (Logo: ) , ... the industry including definitions, classifications, applications and industry ... for the international markets including development trends, competitive ...
(Date:11/24/2015)... , Nov. 24, 2015 Halozyme Therapeutics, Inc. (NASDAQ: ... in New York on Wednesday, December 2 ... Torley , president and CEO, will provide a corporate overview. ... York at 1:00 p.m. ET/10:00 a.m. PT . ... relations, will provide a corporate overview. --> th ...
(Date:11/24/2015)... -- Clintrax Global, Inc., a worldwide provider of clinical research services headquartered ... the company has set a new quarterly earnings record in Q3 ... posted for Q3 of 2014 to Q3 of 2015.   ... , with the establishment of an Asia-Pacific ... United Kingdom and Mexico , with ...
(Date:11/24/2015)... 2015 --> ... released by Transparency Market Research, the global non-invasive prenatal ... of 17.5% during the period between 2014 and 2022. ... Industry Analysis, Size, Volume, Share, Growth, Trends and Forecast ... market to reach a valuation of US$2.38 bn by ...
Breaking Biology Technology:
(Date:11/9/2015)... 2015 ... "Global Law Enforcement Biometrics Market 2015-2019" ... ) has announced the addition ... Market 2015-2019" report to their offering. ... ) has announced the addition of ...
(Date:11/2/2015)... Calif. , Nov. 2, 2015  SRI International ... million to provide preclinical development services to the National ... contract, SRI will provide scientific expertise, modern testing and ... variety of preclinical pharmacology and toxicology studies to evaluate ... --> The PREVENT Cancer Drug Development Program ...
(Date:10/29/2015)... 2015 Daon, a global leader in mobile ... a new version of its IdentityX Platform , ... America have already installed IdentityX v4.0 and ... FIDO UAF certified server component as an ... FIDO features. These customers include some of the largest ...
Breaking Biology News(10 mins):