Abstract

Metal microneedles have been attractive in many fields including nano-scopic imagers, energy-saving field emission displays, and biomedical nano-electro mechanical systems. Several methods for fabrication of metal microneedles have been proposed. However, they involve mostly a bottom-up technique based on several chemical processes, and their time and cost efficiencies are limited. In recent years, we have proposed a new method of microneedle fabrication on metal surface based on laser ablation with optical vortex pulses[1,2]. This technique is capable of forming a metal microneedle by deposition of merely a few laser pulses onto a metal target, significantly saving the time and cost of fabrication of two-dimensional metal microneedle arrays. The resulting needles show a height of >10 μm above the target surface and a tip diameter of less than 0.5 μm.

© 2011 Optical Society of America