Improved resolution of local metal deposition by means of constant distance mode scanning electrochemical microscopy

The potential assisted ion-transfer between two immiscible electrolyte solutions has been implemented in scanning electrochemical microscopy (SECM) for depositing metal microstructures on conducting surfaces. An improved approach for local metal deposition is presented, taking advantage from a recently described non-optical shear-force detection system integrated in the SECM, which provided a current-independent tip-surface distance positioning. This allowed positioning of the micropipette in very close proximity to the surface without applying a potential during the approach, and hence, resulted in an improved resolution for metal deposition. Moreover, it allowed the use of potential pulses for a discontinuous delivery of metal ions over the liquid-liquid interface. The advantages of this approach and its applicability for creating micro- and nanostructures are discussed.