Investigating open and closed dielectric elastomer structures for the development of a soft flexible and stretchable pressure sensor array for pressure injury prevention

Abstract

A pressure injury is a complex chronic wound that forms when the delivery of oxygen and nutrients to soft tissue regions is compromised due to prolonged pressure, commonly over bony prominences, which results in local ischemia, cell death and potentially fatal infections. Its early diagnosis and prediction are challenging, despite technological advancements. It remains one of the most burdensome, costly and fatal secondary medical conditions, which affects millions of people annually. Here, we present a soft, flexible and stretchable pressure sensor array made out of silicone elastomer material, carbon black particles and stretchable, conductive, silver-plated fabric. Its working principle is based on capacitive sensing, where electrodes form an array of parallel plate-like capacitors that enable the detection of pressure due to the deformation of the dielectric layer. We explored a variety of different dielectric architectures consisting of pillar structures of various shapes that make it compressible and potentially increase sensitivity. The sensor array is designed to be shape-conformable, scalable in size and resolution, and able to detect and measure pressure within the desired pressure range for pressure injuries (0-200 mmHg) over short (≤15 minutes) and long periods (≥8 hours) with consistent accuracy and low repeatability error.