Low-Voltage Reversible Electro-Adhesion of Ionoelastomer Junctions

An ionoelastomer is a soft and liquid-free ion conducting network formed by polymerization of an ionic liquid monomer and crosslinker into an elastomer network, such that one ion species is anchored by the network while the other species is mobile. An ‘ionic double layer’ (IDL) is formed at the interface between two oppositely charged ionoelastomers, analogous to the depletion (or space charge) layer formed at a p/n junction of electronic semiconductors. Here, we investigate how the voltage drop across the IDL can be modulated to reversibly control the adhesion between two ionoelastomers. The large electric field developed across the IDL allows for strong adhesion at potentials as low as ~ 1 V, while conventional dielectric electro-adhesives typically require much higher operating voltages (> 1 kV). These ionoelastomer electro-adhesives are also more efficient with regard to force capacity per electrostatic energy, and robust to defects or damage. Our findings provide new fundamental insight into low voltage electro-adhesion and broaden its possible applications.