Out-of-plane polymer hollow micro needle array integrated on a microfluidic chip

This paper presented a novel method for the fabrication of out-of-plane hollow polymer micro-needle arrays. This method of the fabrication combined two different back-side exposure procedures was able to produce hollow micro needles with a nearly vertical internal wall and a tapered outside wall by one lithography step. Micro-fluidic channels can be integrated with the needle array by this approach simultaneously. The arrays are able to fabricate on a flexible membrane such as PDMS for compliant applications. Different types of the needles had been successfully realized and demonstrated in this paper