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Researchers at UC Riverside have developed a revolutionary pressure sensor that indicates pressure by changing its color. 

According to researchers the technology can be applied to variety of applications including everyday devices like smartphones that for operation rely on the right amount of pressure applied to them. 

"We have developed a high-resolution pressure sensor that indicates pressure by varying its color - a sensor that all of us can use with just our eyes," said Yadong Yin, an associate professor of chemistry, whose lab led the research, in the press release. 

Researchers used a self-assembly method to string together gold nanoparticles which was later embedded into a polymer film. The film deformed when pressed, stretching the gold nanoparticle strings by increasing the separation between neighboring gold nanoparticles, the press release read. 

"This increased separation alters the way the nanoparticles interact with light," Yin added. "When linked together, the gold nanoparticles originally appear blue. But they gradually change to red with increasing pressure as the nanoparticles start disassembling. This easily and visually helps us figure out how much pressure has been applied."

Researchers said their sensor differed from commercially available ones. These indicate pressure by changing the intensity of just one color whereas those produced a mosaic of easy-to-distinguish colors. The newly developed sensors also has the benefit of higher contrast and resolution. 

"The many electronic stress sensors commercially available are bulky and not suitable for certain applications," Yin said in the press release. "For example, it is difficult to tell the stress distribution over a particular area if the contact surfaces are not flat and uniform. Our sensor films can be painted on the contact surfaces so that the color variance in different areas clearly shows the stress distribution over the contact surface."

Results of the study will appear in the journal Nano Letters.