Design and experimental characterization of resistive force transducers manufactured via screen-printing

Abstract

This paper presents a systematic methodology for the development of resistive force transducers (RFTs), tailored for robotics, particularly for applications in assistive technologies such as exoskeletons. RFTs are sensors that alter their electrical resistance in response to applied force, pressure, or mechanical stress. Their adjustability, flexible design, cost-effectiveness, and ability to be easily positioned at contact points without compromising user comfort make them ideal for mapping pressure distributions over defined and limited areas. To this end, the current study aims to leverage screen printing, a scalable and cost-efficient manufacturing technique—to enable high-precision customization of sensor structures and conductive inks with tailored properties. The fabricated RFTs were integrated into Co-Ex, a bipedal exoskeleton equipped with a lower-body framework designed to assist individuals with mobility impairments. The performance of the custom RFTs was rigorously evaluated in realistic testing scenarios and benchmarked against commercially available RFTs of comparable size and specifications. Key performance metrics, including center of pressure (CoP) measurements, demonstrated that the custom RFTs exhibited performance comparable to their commercial counterparts, with CoP measurements showing strong agreement. This work highlights the potential of custom RFTs as cost-effective, flexible solutions for advanced robotics and assistive technologies.