Fig. 1.

Switchable wet adhesion concept and demonstrations (also see Movies S1 and S2). (A) Concept: Top and bottom states are static equilibria, characterized by zero power consumption. Moving from one equilibria to the other is accomplished by pumping liquid into or out of the device (pump not shown). (B) Substrate-pendant experiment, with device (Upper Left) holding a Plexiglas substrate (2 cm × 2 cm, arrow points to substrate). Oscilloscope shows “attach” voltage pulse. (C) Device-pendant experiment, with device (arrow points to top surface, visible through Plexiglas substrate) holding its own weight plus a payload for over 7 min at zero voltage. (D) Substrates successfully tested in (B), left to right: plywood, sandpaper, linoleum, brick, and roof shingle. (E) Slim-profile device: 2 cm wide, 1.1 mm thick, ϵ = 300 μm, and ϕ = 0.1. Electrode interconnects to either side, filling port extends down the middle, and no spacer is present here.