Superhydrophobic membranes with electrically controllable permeability and their application to 'smart' microbatteries

Electrically-tunable membranes with controllable permeability have been proposed and experimentally demonstrated by combining nano- and micro-structured superhydrophobic surfaces with the phenomenon of electrowetting. Electrowetting allows dynamical tuning of the contact angle that the liquid forms with the walls of the membrane pores, thus controlling the flow of the liquid through the membrane and, therefore, tuning the permeability of the entire structure. "Smart" electrochemical energy storage cells that can be activated on demand have been built by combining these membranes and microfabricated Zn/MnO2 electrodes. Typical open-circuit voltage of 1.5 V and capacity of 200 Ah/cm2 have been demonstrated.