A liquid-metal RF shunt switch is presented that combines a dielectric spacer over the RF path with electrolyte-filled capillary troughs to facilitate low-power electrical actuation. The switch demonstrates between 20and 30-dB isolation in the dc to 5-GHz range, and greater than 10-dB isolation from 5 to 11 GHz. This switch has between 0.2and 1.2-dB insertion loss from dc to 5 GHz.