Gray Matter Research Microdrives utilize a screw-driven mechanism to bi-directionally control electrode position along a single axis. Each actuator consists of a lead screw, an eccentric brass shuttle and a compression spring. The uninsulated end of each electrode is bonded to a shuttle using a conductive epoxy and the electrode/shuttle assembly is loaded into the microdrive using a multistep sequence. This actuator provides an electro-mechanical interface for controlling electrode movement and maintaining an electrical connection from the electrode tip to the headstage.