Skin-biopsy devices are provided that include a retractable coring assembly. Each spring is interwoven with at least one other spring thereby forming an entirely polymer-coated structure. The coiled tubing unit is configured to move relative to the drilling rig in both longitudinal and lateral directions. In response to a failure of the first network element, the second network element is configured to take over processes of the network transaction from the first network element using the obtained connection states without user interaction of the client. As a result, conductivity of the electrode window is improved and, at the same time, a thickness compared to conductivity of the window electrode is reduced.