  Soft adhesive pads are needed for many robotics applications, and one
approach is based on electroadhesion. Here we present a general analytic model
and numerical results for electroadhesion for soft solids with arbitrary
time-dependent applied voltage, and arbitrary dielectric response of the
solids, and including surface roughness. We consider the simplest
coplanar-plate-capacitor model with a periodic array of conducting strips
located close to the surface of the adhesive pad, and discuss the optimum
geometrical arrangement to obtain the maximal electroadhesion force. For
surfaces with roughness the (non-contact) gap between the solids will strongly
influence the electroadhesion, and we show how the electroadhesion force can be
calculated using a contact mechanics theory for elastic solids. The theory and
models we present can be used to optimize the design of adhesive pads for
robotics application.
