Integrated individually addressable microneedle arrays for robust glucose monitoring and on-demand insulin releasing

Real-time glucose monitoring and adaptive insulin administration are critical for effective diabetes management. Minimally invasive microneedle-based glucose monitoring sensors offer a promising approach but suffer from signal drift due to tissue reactions, inconsistent implantation, or mechanical damage to their sensitive layers during insertion. Moreover, microneedle-based insulin delivery faces limitations in achieving accurate and quantitatively controlled release due to its passive response mechanism. Here, we report a minimally invasive platform integrating a multiplexed glucose biosensor array with on-demand insulin delivery for precise glycemic control. To prevent the impact of potential individual microneedle failure post-insertion, the system incorporates a redundant sensing array comprising four individually addressable electrodes functionalized with glucose oxidase, providing robust and reliable glucose measurements. Simultaneously, an addressable drug-release array of eight microneedles loaded with insulin within redox-responsive hydrogels enables localized electrochemical triggering for spatiotemporally controlled insulin release. These components are coordinated via a wireless interface leveraging real-time multi-channel ADC data processing and Bluetooth transmission to dynamically activate insulin microneedles based on algorithmic glycemic thresholds. The platform's redundant sensing design enhances system reliability, maintaining accurate glucose monitoring even in case of individual sensor failure, while its on-demand insulin release enables real-time glycemic regulation. Ultimately, in vivo experiments in rats were conducted to verify the system's efficacy. By synergizing multiplexed biosensing, fault tolerance, and programmable drug delivery, this platform addresses critical limitations of current glucose monitoring systems and establishes a demonstration prototype for next-generation closed-loop bioelectronics.