A reverse electrochemical floating-layer technique of SPM tip preparation

Presents an experimental set-up involving a combination of reverse electrochemical etching and the floating layer technique of tungsten tip preparation for scanning probe microscopes. Only DC bias is used, avoiding the shortcomings of AC bias. This cost- and time-effective, in-laboratory approach yields two sharp tips in a single etching process with mechanical auto-breaking of the circuit. The nature of the tip shape arising from the floating layer technique is explained in terms of the electrical field distribution between the electrodes. (Original abstract - amended)