Electroactive soft contacts: Controlling adhesion and friction in dry and lubricated interactions

This work investigates the effect of electroadhesion on the smooth soft contact mechanics between a silicone rubber ball and a glass slide, both functionalized to be electroactive and biocompatible. In particular, the influence of electroadhesion on the pull-off force, real contact area, and friction force is experimentally studied using a lab-made tribometer both in dry and wet contact conditions. The role of the applied voltage frequency, interface dielectric properties and crack viscoelasticity is also theoretically disclosed. The results show that the interface electric potential can be designed to precisely control the contact mechanics, including friction and adhesion, thanks to the additional Maxwell stresses applied to the contact, either in dry and lubricated conditions. This is of particular interest for tribotronics, soft robotics and biointerface technologies.