Wet Etched Pyramidal Microneedles With Fluid-Delivery Microchannels

A number of designs for microneedles have recently been developed to facilitate the painless injection of medications, such as insulin, into the human body [1–6]. The injections are painless because the needles penetrate the skin predominantly in the epidermal layer of skin which contains no nerve endings. Some microneedles do not contain inner channels and are simply coated with medication, the intent being that the transdermal drug delivery will take place through absorption over time. A more effective method of medicinal transfer is to equip the microneedles with an inner channel to facilitate rapid delivery of the medication to the skin.