MIT Engineers Develop Light-Activated Soft Gel for Wearables and Robotics

New ionotronic material could enable self-adaptive systems and soft machines.

Apr. 17, 2026 at 7:22am

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A highly textured, abstract painting in earthy tones featuring sweeping geometric arcs, concentric circles, and precise botanical spirals, conceptually representing the dynamic control of ion populations in a soft, flexible material through the application of light.A new light-activated gel developed at MIT could enable self-adaptive wearables, soft robotics, and other flexible technologies.Cambridge Today

Researchers at the Massachusetts Institute of Technology have developed a soft, flexible gel that dramatically changes its conductivity when exposed to light. This breakthrough in the emerging field of ionotronics could lead to new applications in wearable technology, human-machine interfaces, soft robotics, and more.

Why it matters

The ability to dynamically control the ion population in a soft material through light exposure could enable the creation of self-adaptive systems that can automatically respond to environmental changes. This represents a major step forward in bridging the gap between rigid electronics and the soft, squishy nature of biological tissues.

The details

The key to the new material is a class of compounds called photo-ion generators (PIGs) that can become up to 1,000 times more conductive when exposed to light. The MIT team incorporated a PIG into a polyurethane rubber using a swelling method, resulting in a soft gel that can switch between insulating and highly conductive states. While the current version has an irreversible change in conductivity, the researchers believe future iterations could switch back and forth, opening up even more possibilities.

  • The research was published online recently in the journal Nature Communications.
  • The lead author, Xu Liu, is a former MIT postdoc who is now an incoming assistant professor at King's College London.

The players

Thomas J. Wallin

The John F. Elliott Career Development Professor in MIT's Department of Materials Science and Engineering and leader of the research.

Xu Liu

The first author of the paper and a former MIT postdoc who is now an incoming assistant professor at King's College London.

Massachusetts Institute of Technology

The university where the research was conducted.

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What they’re saying

“We've found a mechanism to dynamically control local ion population in a soft material. That could allow a system that is self-adaptive to environmental stimuli, in this case light.”

— Thomas J. Wallin, The John F. Elliott Career Development Professor in MIT's Department of Materials Science and Engineering

“What we're doing is using light to switch a soft material from insulating to something that is 400 times more conductive.”

— Xu Liu, Former MIT postdoc, now incoming assistant professor at King's College London

What’s next

The researchers are confident that future versions of the light-responsive gel could switch back and forth between insulating and conducting states, opening up even more potential applications. They also plan to explore materials that respond to other environmental stimuli like heat or magnetism.

The takeaway

This breakthrough in ionotronic materials represents a significant step towards bridging the gap between rigid electronics and the soft, adaptive nature of biological systems. The ability to dynamically control ion populations in soft materials through light exposure could enable a new generation of self-adaptive wearables, human-machine interfaces, and soft robotics.