3D-printed microneedle arrays for real-time interstitial fluid glucose monitoring

Efficient, accurate, and real-time blood glucose monitoring is crucial for diabetes management. Using interstitial fluid (ISF) instead of blood for monitoring is a key focus. However, microneedle-based in-situ methods face challenges in comfort and miniaturization. This study presents a novel wearable patch for ISF glucose monitoring. The patch features a miniature square microneedle array (MNA) connected to the substrate via microstructure, ensuring strong fixation and easy replacement. The MNA is 3D-printed, offering personalization, efficiency, low cost and biocompatibility. Through the design of the microneedle arrangement on the array, an innovative circular array microneedle configuration is utilized to reduce insertion difficulty and enhance long-term wear comfort by reducing issues related to skin elasticity. Its surface is modified with a bonding, conductive, and functionalized layer for accurate glucose monitoring after insertion. Experimental results show the sensor's high sensitivity and selectivity for real-time ISF glucose monitoring, suitable for both healthy individuals and diabetics. The device is painless, compact, flexible, low-cost, and comfortable, with replaceable electrodes, making it promising for practical diabetes management.