Extremely robust and conformable capacitive pressure sensors based on flexible polyurethane foams and stretchable metallization

Abstract

Microfabricated capacitive sensors prepared with elastomeric foam dielectric films and stretchable metallic electrodes display robustness to extreme conditions including stretching and tissue-like folding and autoclaving. The open cellular structure of the elastomeric foam leads to significant increase of the capacitance upon compression of the dielectric membrane. The sensor sensitivity can be adjusted locally with the foam density to detect normal pressure in the 1 kPa to 100 kPa range. Such pressure transducers will find applications in interfaces between the body and support surfaces such as mattresses, joysticks or prosthetic sockets, in artificial skins and wearable robotics.