Hydrogel tip attached quartz tuning fork using elastomeric tip mold replicated from electrochemically etched tungsten wire

Abstract

This paper reports the first demonstration of hydrogel atomic force microscope (AFM) tip attachment to quartz tuning forks (QTFs) by using elastomeric tip molds replicated from an electrochemically etched tungsten wire. The tungsten tip of ∼20 nm radius obtained by time-controlled electrochemical etching is replicated with h-polydimethylsiloxane (h-PDMS) to make negative conical tip molds large enough to be used for QTFs. Using the h-PDMS tip molds, a polyethyleneglycol-diacrylate (PEG-DA) tip is attached to various facets of QTFs without using an adhesive. In addition, we have shown that hydrogel tip can be regenerated multiple times to address issues associated with tip wear.