A device includes a connected array of cells formed in a stack of flexible sheets. Each pair of adjacent sheets in the stack includes a first sheet and a second sheet bonded together at multiple bond locations. Each sheet has an electrically conductive layer disposed on an electrically non-conductive layer, the conductive layer comprising an electrically conductive non-metal material. Each pair of adjacent sheets in the stack is arranged so that the non-conductive layer of each first sheet is between the conductive layers of the first and second sheets. The cells of the array reversibly transition between an open state and a closed state in response to an electric potential having a magnitude greater than a threshold value applied between the conductive layers of the first and second sheets.