Fabrication and characterization of all hydrogel cantilevers for atomic force microscopy applications

This paper reports a novel method for fabricating hydrogel based microcantilevers by using dynamic mask lithography. A hydrogel, polyethyleneglycol diacrylate (PEGDA), was introduced between two parallel polydimethylsiloxane (PDMS) guides then cured with ultra-violet (UV) exposure to intended shape and size defined by the dynamic mask; an image sent from a PC to a liquid crystal display projector. One PDMS guide has an embedded glass piece which serves as a handle for the microcantilever and the other guide is with or without an inverted pyramid tip mold to fabricate tip-integrated or tipless microcantilevers, respectively. After fabricated hydrogel microcantilevers were thoroughly characterized by using a stylus profilometer and an atomic force microscope (AFM), they were employed for both contact and non-contact mode AFM imaging. In case of non-contact mode, the imaging performance of hydrogel AFM cantilevers was comparable to that of commercial silicon AFM cantilevers.