Tapered metal microneedles fabricated by the hybrid process of mechanical dicing and electrochemical corrosion for drug delivery

Metal microneedles are fabricated by the process of cutting and electrochemical corrosion. The fabricated microneedles are 400 µm in length, 700 µm in space and have sharp tapered tips. In a force test, these microneedles could penetrate an artificial skin and a rat's skin well and safely. In a vitro transdermal drug delivery test, the amount of the permeated flux of calcein and of the bovine serum albumin through the treated rat skin increased by 35 and six times than that on the intact skin, respectively.