PVC gel-based electro-adhesion on extremely rough surfaces

Electrostatic adhesion, also known as electro-adhesion, has been employed in many robotic devices for dynamic adhesion and shows fast switching between adhesive/non-adhesive states on demand. However, a well-known challenge for electro-adhesion is to achieve strong adhesion on rough surfaces with a reasonably low operating voltage. Herein, we report a simple strategy to fabricate electro-adhesion pads based on polyvinyl chloride (PVC) gel, which can achieve strong adhesion (ten times stronger than silicone rubber-based electro-adhesion pads) on rough conductive surfaces with a relatively low operating voltage (<1 kV). When a PVC gel is subjected to a DC voltage, its local creep deformation can increase the contact area between the gel and the rough surface, which enhances the adhesion strength. We experimentally measure the electro-adhesion strength of PVC gel pads in both lap shear and pull-off adhesion tests. Compared to silicone rubber-based electro-adhesion pads, PVC gel pads show much higher adhesion strength in both loading conditions with a lower operating voltage. Finally, we showcase a proof-of-concept demonstration of the electrically controllable adhesion between a PVC gel pad and rough conductive surfaces.