Conductive Sensing Jamming Layers for Resistive Sensing of Layer Jamming Brakes

Abstract

Layer jamming brakes exhibit variable stiffness with vacuum pressure, allowing them to restrict relative motion between two points. These devices hold significant potential for wearable applications due to their lightweight nature and ability to generate substantial linear tension for load transfer or selective movement restriction. However, the challenge of integrating displacement sensors within their structure has not yet been solved. In this article, we introduce a layer jamming system with resistive sensing jamming layers. The proposed mechanism leverages the relative motion of internal overlapping sensing jamming layers to produce a variation in resistance which can inform the user about their relative displacement while also producing frictional forces. This sensing approach is inherently synergistic with the mechanism of the device as it simultaneously generates friction and enables real-time displacement measurement without altering the shape of the device. The proposed device can generate a tensile force of up to 1017 N, can sense displacements over the entire range of operation of jamming layer brakes (up to 82% displacement) with a gauge factor of 1.15 and a linearity error within 1%. We demonstrate its application as a wearable device with a controllable braking point algorithm and as an upper-arm support system.