Researchers have devised a way to create pressure sensors that change colors when applied with force. This multi-use innovation could be used when designing multiple items, from safer vehicles to baseball gloves.
Yadong Yin, an associate professor of chemistry from the University of California, Riverside, worked with his colleagues to successfully develop a high-resolution sensor that can be painted over different kinds of surfaces. One of the most important applications of the sensor is that it is triggered by pressure, an omnipresent force. The sensor will help further studies on how pressure affects the motion and state of matter, a statement from Yin read.
Yin further explained that existing sensors in the market today cannot withstand the pressure given off by large pieces of metal. They're also usually equipped with color indicators that are difficult to interpret and understand. To overcome these limitations, researchers used nanoparticles so small that 1,000 of them could fit within the width of a single human hair.
The pressure sensor is created by tiny gold nanoparticles that are attached to each other in a chain-like manner. When the chains are disrupted due to applied pressure, the sensor changes its color. The pressure sensor has a deep blue color in its relaxed state which then changes to ruby red when hit with force.
"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", Yin said in a press release. "Our colorimetric sensor film changes color, not just color intensity, which gives us the benefit of higher contrast and resolution. We also can make it into a liquid, which can be painted on objects such as crash test dummies that have complex surfaces," he added.
This study, titled Colorimetric Stress Memory Sensor Based on Disassembly of Gold Nanoparticle Chains, was published in the April 30 issue of Nano Letters.
