Symposium SB05: Biohybrid and Soft Functional Interfaces

Lawrence Renna, Intelligent Optical Systems, USA

Microneedle Array Optical Sensing for Wearable Real-time Hydration Monitoring

Written by Birgul Akolpoglu

Lawrence Renna's talk on wearables addressed the critical need for real-time hydration monitoring, particularly in long-duration missions where pilot performance is impacted by insufficient water intake. Their engineered device involves a transparent microneedle array embedded with sensors and optics for continuous probing of interstitial fluids. Using a combination of materials including PDMS, Polyhydroxyethylmethacrylate (pHEMA) hydrogel, and polyester film, they created a microneedle sensor patch capable of monitoring individual biomarker levels. The sensors included pH, water activity (Aw), and sodium (Na). By leveraging the solvent polarity and proton-donating ability, the technology measures phase-resolved luminescence. Testing on porcine and PDMS-based mechanical skin models revealed no adverse effects, and a human study demonstrated the array's effectiveness as a physiological monitor during exercise. The promising results set the stage for a larger human subject study next year, showcasing the potential of microneedle array optical sensing in enhancing hydration monitoring for various applications.