Foam Pressure Mapping with Optimized Electrodes

Nano-composite piezo-responsive foam (NCPF) is an inexpensive foam that can be used to measure a static load while still providing a comfortable interface. The purpose of this study was to create a modularized foam-based pressure measurement system. A measurement system was developed that uses an interdigitated electrode applied to the NCPF. Applied pressure changes the impedance of the NCPF, which, in turn, is converted into a voltage using a voltage divider. A modular measurement system is described that uses an ATtiny 1627 microcontroller to measure the pressure at nine electrodes. The nine electrode modules are controlled by an ESP32 microcontroller that aggregates the data and wirelessly transmits the data to a tablet. The modular system was demonstrated with 1008 individual electrodes. The characterization of the electrode combined with the NCPF is presented, along with optimization of the electrode geometry.