Collaboration develops flexible thermistor with wireless radio frequency interface

The sensor developed by the team from the Universities of Glasgow, Southampton and Loughborough is made from a composite of carbon fibres and silicon rubber, and is said to work without battery power or onboard processing.

The flexible sensor’s ability to absorb and reflect radio frequency (RF) signals varies with atmospheric heat or cold, enabling the sensing of temperature across a much greater range than other comparable devices. It can also withstand thousands of cycles of bending and stretching without losing its sensitivity to temperature.
Temperature sensors are found in almost all electronic devices, and the global market for the technology is currently valued between $5-8bn.

Typical temperature sensors – thermistors - work by changing resistance in response to changes in temperature. However, they are usually only capable of measuring over narrow ranges of temperature variation, meaning temperature sensors often rely on an array of different thermistors to cover a wide sensing range.
The new soft, flexible temperature sensor, developed by a team led by researchers from Glasgow, can read temperatures from 30°C to over 200°C.
This could make help make future wireless sensors cheaper and more sustainable, as fewer devices will now be required to cover the same temperature sensing range.
In a paper published in Nature Communications, the researchers show how they used a 3D printer to mould the flexible material and integrated it into components like antennas, RFID labels, and resonators. Then they tested its ability to absorb RF radiation at different temperatures ranging up to 300°C.