Oscillating gel acts like artificial skin, giving robots potential ability to ‘feel’

April 1, 2012
Smiley Gel

Smiley face made of gel. University of Pittsburgh and MIT researchers have accomplished the first demonstration of oscillating gels that can be "revived" by mechanical pressure (credit: University of Pittsburgh)

gel can be resuscitated in a fashion similar to a medical cardiopulmonary resuscitation, researchers from the University of Pittsburgh and the Massachusetts Institute of Technology (MIT) have demonstrated.

These findings pave the way for new applications — like artificial skin for robots — that sense mechanical stimuli and respond chemically; this is a natural phenomenon few materials have been able to mimic.

The Pitt researchers made predictions regarding the behavior of Belousov-Zhabotinsky (BZ) gel, a material that was first fabricated in the late 1990s and shown to pulsate in the absence of any external stimuli. In fact, under certain conditions, the gel sitting in a petri dish resembles a beating heart.

Along with her colleagues, Anna Balazs, Distinguished Professor of Chemical and Petroleum Engineering in Pitt’s Swanson School of Engineering, predicted that BZ gel not previously oscillating could be re-excited by mechanical pressure. The prediction was actualized by MIT researchers, who proved that chemical oscillations can be triggered by mechanically compressing the BZ gel beyond a critical stress.

“Think of it like human skin, which can provide signals to the brain that something on the body is deformed or hurt,” says Balazs. “This gel has numerous far-reaching applications, such as artificial skin that could be sensory — a holy grail in robotics.”

Balazs says the gel could serve as a small-scale pressure sensor for different vehicles or instruments to see whether they’d been bumped, providing diagnostics for the impact on surfaces.

Ref.: Irene Chou Chen, et al., Mechanical Resuscitation of Chemical Oscillations in Belousov–Zhabotinsky Gels, Advanced Functional Materials, 2012; [DOI:10.1002/adfm.201103036]