Innovative Wet Etch Processing Microneedles derma roller

2012-10-30 06:51:29

Innovative Wet Etch Processing Microneedles derma roller
Microneedles have been made using a variety of fabrication processes in diverse materials such as metals, glasses, sugars, plastics and polymers. The Tyndall National Institute, which leverages over €200M in high-tech research infrastructure, is a world leader in the fabrication of silicon microneedles using wet etching technology, which involves depositing thin glass-like squares (known as masks) on a thin disk or wafer of silicon, and then placing the wafer – which has a very precise crystal structure – into a hot bath of potassium hydroxide for several hours. Very tight process control is achieved through an acquired in-depth knowledge of etch rates across the many crystal planes in a silicon wafer, allowing a precise identification of the exact endpoint required to produce an array of sharp-tipped needles. The interaction between the mask shapes, the crystal planes of the silicon and the etchant results in the formation of octagonal cone-shaped microneedles. These ultrasharp needles have extremely smooth surfaces and exhibit excellent mechanical and structural robustness. Both solid and hollow needles have been fabricated, and  by using silicon masters and micromoulding procedures, the microneedle arrays can also be replicated in polymeric materials.