Sooner than later, robots may have the ability to "feel." In a paper published online March 26 in Advanced Functional¹ Materials, a team of researchers from the University of Pittsburgh and the Massachusetts Institute of Technology (MIT) demonstrated that a nonoscillating（非振荡） gel can be resuscitated² in a fashion similar to a medical cardiopulmonary resuscitation³（心脏复苏术） . These findings pave the way for the development of a wide range of new applications that sense mechanical stimuli⁴ and respond chemically -- a natural phenomenon few materials have been able to mimic⁵.

A team of researchers at Pitt made predictions regarding the behavior of Belousov-Zhabotinsky (BZ) gel, a material that was first fabricated in the late 1990s and shown to pulsate⁶ in the absence of any external stimuli. In fact, under certain conditions, the gel sitting in a petri dish（有盖培养皿） resembles a beating heart.

Along with her colleagues, Anna Balazs, Distinguished⁷ Professor of Chemical and Petroleum⁸ Engineering in Pitt's Swanson School of Engineering, predicted that BZ gel not previously⁹ 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 deformed¹⁰ or hurt," says Balazs. "This gel has numerous far-reaching applications, such as artificial skin that could be sensory¹² -- a holy grail in robotics."

Balazs says the gel could serve as a small-scale pressure sensor¹¹ for different vehicles or instruments to see whether they'd been bumped, providing diagnostics for the impact on surfaces. This sort of development -- and materials like BZ gel -- are things Balazs has been interested in since childhood.

"My mother would often tease me when I was young, saying I was like a mimosa plant -- shy and bashful," says Balazs. "As a result, I became fascinated with the plant and its unique hide-and-seek qualities -- the plant leaves fold inward and droop¹³ when touched or shaken, reopening just minutes later. I knew there had to be a scientific application regarding touch, which led me to studies like this in mechanical and chemical energy."

Also on Balazs's research team were Olga Kuksenok, research associate professor, and Victor Yashin, visiting research assistant professor, both in Pitt's Swanson School of Engineering. At MIT, the work was performed by Krystyn Van Vliet, Paul M. Cook Career Development Associate Professor of Material Sciences and Engineering, and graduate student Irene Chen.

Funding for this research was provided by the National Science Foundation and the U.S. Army.