From Conventional Non-Conductive Foams to Soft Piezoresistive Pressure Sensors: A Low-Cost Approach to Large-Area Pressure-Mapping

Abstract

This article presents a low-cost, and scalable method for synthesizing large sheets of functionalized foam for soft resistive pressure sensing that is compatible with any commercially available non-conductive foam. The process is illustrated by soaking Pu (Polyurethane) foam in a carbon-based polymeric mixture resulting in a functional foam with large pressure detection range up to 500 kPa, while retaining its deformability and recoverability after cyclic compression. The foam also shows unprecedentedly fast response time of 120 ms. The foam was integrated in a wearable respiration sensor and in a large multitouch sensing mat that allows for precise data acquisition on the position and intensity of various simultaneous touches without the occurrence of ghost touches.