Fluid-coupled hollow metallic microfabricated needle arrays

In this paper, fluid coupled metallic micromachined needle arrays are designed, fabricated, and characterized. The described hollow metallic needle arrays include design features such as dual structural supports and needle coupling channels. The supports and needle walls are formed by micro-electroformed metal to provide increased structural integrity. The needle coupling channels are used to fluidically interconnect the needles and allow pressure equalization and balance of fluid flow between needles. In addition, the needle coupling channels minimize the effects of restricted needle passages by providing a redistribution point for fluid flow between them. The optimum design for the needle coupling channels is investigated using an ANSYS finite element numerical model. The significance of this work includes the development of hollow, metallic micromachined needle arrays for biomedical applications, as well as, a discussion of structural, fluidic, and biological design considerations.