Single layer piezoresistive polyimide pressure sensor based on carbon nanotubes

Abstract

This research presents a novel pressure sensor based on integrating multiwalled carbon nanotubes (CNTs) directly in the polyimide layer. The optimal mechanical properties combined with the conductive CNTs give a reliable, yet flexible and thin (4.7 μm) pressure sensor. Due to the direct integration, the need for an additional polymer substrate is eliminated. In this case, the sensor substrate is the sensing layer, keeping the sensor thin and simple. First results show a detectable linear pressure range up to 40N. Cyclic pressure response tests show the repeatability of the sensor and its stable mechanical nature due to its strong polyimide base. Thermal ageing tests show promising long-term stability of the pressure sensors.