Polymeric foams for flexible and highly sensitive low-pressure capacitive sensors

Abstract

Highly sensitive foam sensors High sensitivity is a critical feature for flexible pressure sensors and a novel and low-cost emulsion method has been invented to make capacitive sensors with higher sensitivity. A team of CNRS scientists from France led by Prof Annie Colin develops an unconventional approach for flexible and highly sensitive low-pressure capacitive sensors based on carbon black filled foams. They embed the carbon black in Polydimethylsiloxane (PDMS) elastomer using a water-in-oil emulsion method, which achieves a large change of the permittivity associated to large changes in capacitance upon small compression forces. Consequently, the sensitivity exceeds 35 kPa-1, one order of magnitude higher than previous results. The team then demonstrates arterial pressure measurements and in deed the technique can be applied to much wider fields requiring low-cost and low-power consumption.