Novel electrochemical transistors, based on the conductive polymer PEDOT, operating at driving voltages of only a few volts in bulk material, with little demon substrate planarity, are described by the authors. The underlying polymer ion pair PEDOT:PSS is conductive in both oxidized reduced state. Two transistor architectures, a bi-stable a dynamic transistor (the first electrochemical specimen of its kind) with an on/off ratio of 105 200 Hz modulation speed, were realized._x000D_