Microneedle-based system for minimally invasive continuous monitoring of glucose in the dermal interstitial fluid

We present a minimally invasive continuous glucose monitoring (CGM) device. The system consists in an ultra-miniaturized electrochemical sensor probe (70 × 700 × 50 μm3) inserted into the lumen of a hollow silicon microneedle. The implantable portion of the system is 50-fold smaller than state-of-the-art commercial products, thus enabling glucose monitoring in the dermis and a less invasive insertion procedure. Passive interstitial fluid extraction is achieved, making the daily use of this system practically viable. Moreover, the sensor positioning provides minimal delay in tracking glycaemia (5–10 minutes lag), due to the minimal distance between sensing electrodes and microneedle opening. The demonstrated system has therefore the potential to enable minimally invasive, fast and reliable CGM in patients affected by diabetes.