Field-effect transistor (FET) devices are described herein that include an insulator layer, a plurality of active field-effect transistors (FETs) formed from an active silicon layer implemented over the insulator layer, a substrate layer implemented under the insulator layer, and proximity electrodes for a plurality of the FETs that are each configured to receive a voltage and to generate an electric field between the proximity electrode and a region generally underneath a corresponding active FET. Switches with multiple FET devices having proximity electrodes are also disclosed.