A removable power supply that can be manually inserted and removed from a computer cabinet is disclosed. The connection structure has a first semiconductor device formed on an insulator substrate. A trim ring operatively contacts the first planet for mutual rotation therewith. The anchoring elements are effective to anchor the device to or adjacent a sentinel lymph node accessed by the device. The anode and the cathode generate an electric field along the length of the microcapillary tube, and the plurality of electric field reducing components selectively reduce the electric field at spatial intervals along the length of the microcapillary tube. The apparatus also comprises at least one controller.