Flexible and Stretchable Microneedle Electrode Arrays by Soft Lithography for Continuous Monitoring of Glucose.

Continuous monitoring of glucose (CGM) level is of utmost importance to diabetic patients, especially with no or minimal pain. Microneedle arrays with desired electrode patterns have been fabricated by soft lithographic molding, and the patterned electrodes were formed via shadow evaporation through a shadow mask that was made from a modified molding technique. With immobilization of glucose oxidase (GOx), the microneedle electrode arrays (MEAs) have been successfully employed for the in vitro CGM using impedance spectroscopy. The fabricated MEAs could monitor the varying glucose level continuously for up to ~10 days. Similar processes have been applied for the fabrication of stretchable MEAs, which can conform to complex curvilinear surfaces. The simple and low-cost fabrication of MEAs, either in flexible or stretchable forms, may find various applications in wearable health monitoring techniques.