A conformable microneedle sensor with photopatternable skin adhesive and gel electrolyte for continuous glucose monitoring

Abstract

Wearable microneedle electrochemical sensors require functional soft materials such as gel electrolytes and skin adhesives to electrically and physically integrate with the skin for continuous measurements. However, current patterning methods for these materials have low process compatibility and are generally laborious and time-consuming, making it challenging to use them for various types of devices. Here, we demonstrate a conformable microneedle sensor applied using a photopatternable gel electrolyte and skin adhesive for glucose monitoring. We used oxygen inhibition photolithography to pattern the gel electrolyte and modified a thermocurable adhesive for positive photolithography, enabling precise and direct deposition onto a microneedle substrate. The resulting microneedle sensor establishes a stable electrical and physical interface with skin and is highly sensitive over a broad range of glucose concentrations. We tested the microneedle sensor for diagnosing hyperglycemia in an anesthetized rat through stable, continuous glucose monitoring.