TOWARDS PAIN-FREE AND HIGH-ACCURACY POINT-OF-CARE GLYCEMIC CONTROL USING AUTONOMOUS MICRONEEDLE-BASED SYSTEM

Microneedle systems able to measure glucose concentration in interstitial fluid (ISF) have been recently proposed for pain-free glycaemic control, as an alternative to standard finger-prick systems, following the demonstration that glucose concentration in ISF parallels that in blood, though with a delay time of 10-20 minutes. In fact, besides use of microneedles for transdermal drug delivery applications [1], in the last years an increasing number of studies is being published on their use for transdermal biosensing applications both in-situ and ex-situ, among which glucose monitoring in peripheral blood and ISF is a major target [2]. In this work, a novel class of self-powered microneedle-based transdermal biosensors for pain-free and high accuracy measurement of glycaemia in ISF is reported. Microneedle chips (silicon die 0.5 cm x 0.5 cm) integrating a two-dimensional array of silicon-dioxide hollow needles protruding from the front-side and in connection with a reservoir (18 µL volume) grooved on its back-side are designed, fabricated, and tested. The microneedles feature different pitch p (16 µm@type#A and 10 µm@type#B) and internal diameter d (6 µm@type#A and 4 µm@type#B), but same protruding length (100 µm) and inner lumen length (200 µm).