A flexible, lightweight sensor that is said to respond rapidly to changes in body temperature has been developed by a group from the University of Tokyo. The sensor’s resistance is said to change by up to 100,000 times over a range of 5°C, allowing accurate temperature measurement without additional complicated display circuitry.
The sensor is composed of graphite and a semicrystalline acrylate polymer formed of two monomers. The temperature at which the sensor is most precise can be selected by altering the proportions of the two monomers. The research group measured temperatures between 25 and 50°C, with response times of less than 100ms and a temperature sensitivity of 0.02°C. The device was also found to be stable, providing repeated readings up to 1800 times.
“By printing an array of these sensors, it is possible to measure surface temperature over a large area,” said Professor Takao Someya from the University’s Graduate School of Engineering. “Because the huge response of the sensor to temperature change allows us to simplify the circuitry, we could print our sensors onto adhesive plasters that could then monitor body temperature.”
Other possible applications include wearable electronics, where the sensor could be applied beneath fabric to measure temperature during sporting and other activities.
Author
Graham Pitcher
Source: www.newelectronics.co.uk