On the design of an electronic mosquito: design and analysis of the micro-needle

This paper addresses the design of the Electronic Mosquito. It presents the analysis for the in-plane silicon micro-needles that can be used for drug delivery and/or blood sampling for biomedical applications. The characteristics of in-plane micro-needles are far more reliable than out-of-plane micro-needles for transdermal drug delivery and blood sampling. In order to withdraw blood samples from the subcutaneous fat layer, which occurs at a distance of 2000 to 4000 /spl mu/m below the skin surface, the length of our MEMS based in-plane micro-needle have been set at 3000 /spl mu/m. This length is impractical for out-of-plane micro-needles. Drug delivery and blood samplings place requirement in terms of minimal needle dimensions and force withstanding capabilities, which are inversely related to each other. The strength of the micro-needles has been examined analytically and modeled using finite element modeling tools. Through performance analysis it is shown that the proposed design is a significant improvement over existing micro-needles.