Pressure sensor reveals the colours of stress

Developed at the University of California, Riverside, the technology could also be applied to devices that rely on the application of pressure in order to operate.

The lab of Yadong Yin, an associate professor of chemistry, used a self-assembly method to string together gold nanoparticles which they then embedded into a polymer film. The film deformed when pressed, stretching the gold nanoparticle strings by increasing the separation between neighbouring gold nanoparticles.

‘This increased separation alters the way the nanoparticles interact with light,’ Yin said in a statement. ‘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.’

Study results appear this month in Nano Letters.

The sensor that Yin’s lab developed is said to differ from commercially available pressure sensor films as the latter indicate pressure by changing the intensity of just one colour. They tend to be difficult to interpret and have low resolution and contrast.