Electronic readers that use rugged flexible substrates potentially offer very attractive characteristics (low-cost processing, lightweight, mechanical flexibility, etc.) and could expand the explosive growth of e-reader devices. In this paper, we demonstrate electrowetting (EW) devices fabricated on flexible substrates, including paper, polymers (plastics), and metal foils and sheets. EW devices on some of the flexible substrates exhibit characteristics very close to those of conventional EW devices on glass substrates. Prototypes of flexible EW arrays on plastic substrates are demonstrated to switch reversibly by applying a low voltage difference (20 V). The array operation is maintained even when the display is mechanically flexed. These results indicate the promise of flexible EW devices for mobile and other devices, including video rate flexible e-paper. (C) Koninklijke Brill NV, Leiden, 2011