The sensitive strain sensor that can detect the weight of a feather

Physicists have created the most sensitive strain sensor ever made, capable of detecting a feather's touch. The sensor, developed by the Materials Physics Group at the University of Sussex, can stretch up to 80 times higher strain than strain gauges currently on the market and show resistance changes 100 times higher than the most sensitive materials in research development.

The research team believe the sensors could bring new levels of sensitivity to wearable tech measuring patients' vital signs and to systems monitoring buildings and bridges' structural integrity.

Marcus O'Mara, from the School of Mathematical and Physical Sciences at the University of Sussex, said: ""The next wave of strain sensing technology uses elastic materials like rubber imbued with conductive materials such as graphene or silver nanoparticles, and has been in development for over a decade now.

Commercial gauge devices suffer from relatively low sensitivity and strain range, with gauge factors ranging from 2-5 and maximum strains of 5% strain or less, resulting in the resistance increasing by less than 25% and preventing high-strain sensing required for bodily motion monitoring.

The new sensors are able to detect strains less than 0.1%, due to their higher gauge factor of ~20, and up to 80% strain, where the exponential response leads to the resistance changing by a factor of more than one million.

This allows both high-sensitivity low-strain sensing for pulse monitoring and high-strain measurement of chest motion and joint bending as a result of the record resistance change.