Scientists from the University of California in Riverside (UC Riverside) have unveiled a new type of sensor that can indicate changes in pressure. The new sensor changes color when pressure is applied.
The color changing sensor was developed by UC Riverside researchers led by Yadong Yin. The most common types of pressure sensors used today involved piezoelectric sensors that often require digital readouts to present information about pressure. However, the new sensor developed by Yin and his colleagues can be applied to a wide variety of different objects. The researchers say that their new sensor could be used for cars, clothing and even sporting goods such as baseball bat grip tape. The researchers published their findings in the online journal Nano Letters.
"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 Yin. Yin is an associate professor of chemistry from the UC Riverside.
Measuring pressure is a very important part of human technology. Scientists measure pressure for a wide variety of reasons. From regulating the right amount of gas to pump into a propane tank to measuring the impact on crash test dummies when designing safer vehicles, pressure is an important part of modern life. On a daily basis, humans exert pressure on objects several hundred times per day. Holding a baseball bat or using a smartphone also involves exerting pressure.
For years, scientists have been looking for a better way to measure pressure. Since current sensors are still relatively bulky, they can be difficult to attach to smaller objects like smart phones. Moreover, integrating these sensors into things like clothing can also prove to be difficult. With the new sensor developed by the UC Riverside researchers, adding sensors to a host of different objects can be a lot easier.
The sensors were made using gold nanoparticles that form tiny chains. Exerting pressure on these nanomaterials can interfere with the miniscule chains, which changes the color of the material. While color changing pressure sensors are already available, older sensors often change to a different color of the same hue. This means that reading differences in pressure using similar shades of color can be difficult and confusing. The new nanotechnology based pressure sensor can change color from a deep blue color to a light pink hue.
"This increased separation alters the way the nanoparticles interact with light," Yin said. "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."
Since the sensor can change from one color into a totally different color in response to pressure, reading the sensor can be a lot easier. Moreover, the material is also easy to apply. Since it can be changed into a liquid form, the sensor can simply be painted onto surfaces like baseball grips or even crash test dummies.