Fabrication of rounded knife-edged structure for trans-dermal drug delivery system

We propose a rounded knife-edge structure having a large surface area to increase the dosage amount in the trans-dermal drug delivery system. We fabricated a Si rounded knife-edge structure as the original master by anisotropic wet etching. We then replicated the same shape with biodegradable hyaluronic acid-based material by a molding process. We evaluated the penetration performance of the fabricated knife-edged structures into an artificial skin of a silicone rubber sheet and confirmed that both the Si and biodegradable knife-edged structures successfully penetrated the sheet with an applied load of 180 g. We also fabricated an arrayed biodegradable rounded knife-edged structure that successfully penetrated mouse skin.