Researchers led by Cunjiang Yu at University of Illinois Urbana‑Champaign have achieved a significant milestone in stretchable electronics: the first fully rubber-based circuits that mimic the behavior of standard CMOS (complementary metal-oxide-semiconductor) technology.
The Challenge: Stretchable Circuits vs Rigid CMOS
Traditional CMOS circuits underpin nearly all modern electronics — smartphones, computers, sensors — but they rely on rigid metals, oxides and semiconductors that crack or fail under strain. Stretchable electronics until now have mostly used flexible substrates combined with conventional components, but the fundamental materials remained brittle under significant deformation.
What’s New: Entirely Rubbery Integrated Electronics
Yu’s team developed what they call “rubbery CMOS” — systems in which every functional component, including the semiconductor, dielectric, and interconnects, are made of intrinsically stretchable elastomeric materials. Crucially, they built both n-type and p-type transistors, enabling full complementary operation, a feat not previously demonstrated for rubbery electronics.
Key highlights:
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The circuits maintain stable performance even when stretched by up to ~50 percent.
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Digital logic gates built from these stretchable transistors continue working under large mechanical strains.
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As a demonstration, the team fabricated a thin “sensory skin” that can adhere to human skin while containing the rubbery circuitry.
Why Design Engineers Should Care
For engineers working on wearables, soft robotics, implantable devices or human-machine interfaces, this work opens new possibilities:
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Conformal integration: Circuits that move, bend and stretch along with soft substrates or living tissue.
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Monolithic stretchable systems: Eliminating the need to embed rigid islands or rigid-component islands within flexible substrates.
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New design paradigms: You can start designing devices where the electronic substrate itself is elastomeric, enabling designs that flex, wrap, fold and conform in ways rigid boards cannot.
What to Look For
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Scaling and manufacturing: Will these rubbery CMOS circuits scale to larger area, higher transistor counts, finer feature sizes and industrial throughput?
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Materials variety: Can the elastomeric materials support high-speed switching, high density interconnects and compatibility with standard IC-level performance?
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Integration with other systems: How will these rubbery electronics integrate with sensors, actuators, power systems or communication modules?
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Design tools and workflows: What CAD/CAM or device-modeling tools will emerge to support circuits built on elastomeric platforms rather than rigid ones?
Original Story: Cunjiang Yu develops the first rubber electronics that offer CMOS functionality | Electrical & Computer Engineering | Illinois
