Putting The Pieces Together: Building A Nonenzymatic Wearable Glucose Sensor Using Silicon Microneedle Arrays

We developed the technology to build a novel painless CGM that is an on-body, wirelessly transmitting device that extracts interstitial fluid with a dime-sized patch of microneedles and optically detects glucose from extremely small fluid volumes. We not only developed an innovative method for fabricating silicon microneedles, sharp and small enough to penetrate skin without pain (160 µm in height, 50 µm in diameter, and 100 µm in width), but also demonstrated that our microneedle fabrication is repeatable and reliable. Next we developed an entirely new, stable, non-enzymatic glucose-sensing method based on a variation of the well-known fluorescent-based boronic acid sensor, and further refined this sensor to allow for conductivity based sensing as well as ratiometric sensing of glucose (Figure 1, left). Finally, we built a novel integrated silicon buried dual-junction (BDJ) photodiode-based system with which to detect glucose with our sensor. The Figure attached shows our latest successes with ratiometric sensing of tartaric acid using our microfabricated device (Figure 1, right). Given our results, we believe this technology can now be transitioned to industry, and we are moving on to developing a wearable microfluidic-based patch pump that can allow for a truly affordable artificial pancreas based diabetes management solution. Disclosure S. Pennathur: Board Member; Self; Laxmi Therapeutic Devices. Employee; Self; Laxmi Therapeutic Devices. Research Support; Self; American Diabetes Association, Leona M. and Harry B. Helmsley Charitable Trust. Stock/Shareholder; Self; Laxmi Therapeutic Devices. H. Kim: None. B. Wang: None. B.N. Queenan: None. D. Huber: None. Funding American Diabetes Association/Pathway to Stop Diabetes (1-17-VSN-18 to S.P.)