Characterization of HNA etchant for silicon microneedles array fabrication

Research on microneedles has been increasing rapidly to overcome the drawbacks of hypodermic needle which can results in painful injection, tissue damage and uncontrollable delivery rate. This paper presents process characterization of wet isotropic etching for solid microneedles array development. Work has been carried out to investigate the isotropic etching behavior in 17 different compositions of HNA solution. The experimental responses of vertical etch rate and lateral etch rate are presented. Resulting surface profiles from various HNA compositions are also reported. The etching properties will be applied to develop recipe to fabricate the optimum solid microneedles.