All‐Fabric Wearable Electroadhesive Clutch

A lightweight, textile fabricated, haptic device consisting of an electrostatic adhesive clutch is introduced, which can constrain body movement when activated at low power (≈1 mW). The clutch electrodes are composite structures, prepared by coating copper‐plated polyester fabric with thin films of high‐κ dielectric ink. When voltage is applied across a pair of overlapping electrodes, the charge separation created between the overlapped surfaces gives rise to adhesive forces that resist tensile loads along the electrode surface. The clutch is arranged in parallel with a sheet of knitted fabric, which exhibits low‐stiffness spring‐like characteristics, thus decreasing load resistance when the clutch is deactivated. Mechanical tests are carried out to assess the dependency on scaling and loading rate at different voltages. The load‐bearing capacity of the device is experimentally shown to sustain a 10 kg load for a clutch pair with 120 × 70 mm2 dielectric overlap, when activated at 400 V. Current‐dependent charging and discharging times that can be as low as 15 ms are presented. To exemplify its pertinence in wearable applications, the device is used as an elbow joint constraint, exhibiting its conformability to curvatures and suitability for skin‐mounted applications.