Novel low-cost approach to build large-scale flexible sensors for spatially distributed ground reaction force measurements.

Abstract

Objectives: The objective of this study was to develop and characterize a novel low-cost, flexible sensor system for ground reaction force (GRF) measurements for biomedical applications. The system aims to provide GRF measurements across customizable areas up to 2 m², suitable for integration into various medical and rehabilitation devices.

Methods: The sensor system was constructed using multiple discrete resistive sensor modules. Each module had a quadratic shape and an edge length of 7.5 cm. The system utilized ESD packing-foam as resistive sensing material and conductive textile as electrodes. Measurements were conducted using an Arduino Nano microcontroller, a Wheatstone bridge circuit and analogue multiplexers. A demonstrator, integrating the sensor modules in a sports mat was built to show the functionality.

Results: The proposed system was capable of measuring forces up to 330 N. The sensor modules have an exponential force-resistance characteristic curve and showed inter-module and inter-day variability in the range of commercially available sensor systems' accuracy. The demonstrator enabled to visualize changes in weight distribution on its surface.

Conclusions: The developed sensor system offers a reliable, flexible, and low-cost solution for GRF analysis in biomedical applications, providing data e.g. for rehabilitation feedback.