Sharp tip-separable microneedle device for trans-dermal drug delivery systems

We developed a sharp tip-separable microneedle device for trans-dermal drug delivery systems (DDSs). Two differently shaped Si-microneedles, eight-sided and rhombic pyramids, were first fabricated by photolithography and anisotropic wet etching. Then, a tip-separable biodegradable microneedles tips was fabricated using a molding process. Thanks to the sharpness of the Si-microneedles, sharp biodegradable tips with the radius of less than 1.0 μm could be fabricated. Finally, the tip-separable microneedle device was successfully used to penetrate a piece of mouse skin.