Electrical drill bits

A drill bit comprising:

• (a) a connector, which comprises:
• (i) a shank, configured to receive torque;
• (ii) a proximal electrically-conductive coupler, which is disposed at a distal end of the shank, rotationally fixed with respect to the shank;
• and
• (iii) a distal electrically-conductive coupler, which is (1) rotationally fixed with respect to the proximal electrically-conductive coupler, (2) electrically isolated from the proximal electrically-conductive coupler, and (3) shaped so as to define a distal-electrically-conductive external contact surface;
• and
• (b) a drill shaft, which is shaped so as to define:
• (i) a proximal interface that is rotationally fixed with respect to the proximal electrically-conductive coupler and configured to transfer the torque from the proximal electrically-conductive coupler to the drill shaft, and
• (ii) a distal end portion that is shaped so as to penetrate tissue when rotated, wherein the drill shaft comprises:
• (i) an electrically-conductive outer electrode, which is in electrical communication with the distal electrically-conductive coupler;
• (ii) an electrically-conductive inner electrode, which has a proximal end portion that is in electrical communication with the proximal electrically-conductive coupler of the connector, and is electrically isolated from the distal electrically-conductive coupler of the connector;
• and
• (iii) an electrical isolation layer radially between the electrically-conductive outer electrode and the electrically-conductive inner electrode, so as to electrically isolate the electrically-conductive outer electrode and the electrically-conductive inner electrode from each other.