Increasing the adhesion force of electrostatic adhesives using optimized electrode geometry and a novel manufacturing process

This paper presents a method to increase the adhesion level of electrostatic adhesives by optimizing the electrode geometry and using a novel manufacturing technique. Simulation software, Comsol Multiphysics, was used to find the average electric field strength generated by a specific electrode geometry. The geometry was then optimized based on a gradient descent algorithm that changed each individual electrode width. Four different electrode patterns were simulated: concentric circles, comb (inter-digital), square spiral, and Hilbert curve (a fractal space-filling geometry). Among these designs the concentric circle pattern was the most effective. The optimized concentric circle pattern had varying electrode widths and the smallest allowable gap between the electrodes. These results were experimentally validated on a variety of materials with varying roughness: drywall, wood, tile, glass and steel. Overall, the experimental data closely matched the simulation results. Utilization of a new fabrication process also allowed for a significant increase in shear adhesion capability. With the optimized electrode geometry and the new fabrication process, we are able to achieve between a 2.2 and 15x improvement in shear pressure compared to previously published values, depending on the substrate material. (C) 2014 Elsevier B.V. All rights reserved.