Design and characterization of a self-powered microneedle microfluidic system for interstitial fluid sampling
Christopher T. Sharkey, Angélica F. Aroche, Isabella G. Agusta, Hannah E. Nissan, Tamoghna Saha, Sneha Mukherjee, Jack Twiddy, Michael D. Dickey, Orlin D. Velev, Michael A. Daniele
Abstract
Dermal interstitial fluid (ISF) is a promising source of biomarkers for point-of-care (PoC) diagnostics, yet noninvasive and reliable extraction remains a significant challenge. In this study, we present a fully passive microneedle (MN) platform that integrates hydrogel-forming MNs, a hydrogel-based osmotic pump, and paper microfluidics to enable zero-power ISF extraction and analyte transport from skin models. The system's performance was evaluated using paper microfluidic designs optimized for both bulk fluid uptake and lateral flow-based detection. Osmotic pumping with glycerol and glucose showed comparable extraction efficiencies. Cortisol, a representative stress biomarker, was successfully recovered following 15-minute, 45-minute, and 24-hour sampling durations, demonstrating the platform's suitability for both short-term and extended ISF monitoring. These results highlight the potential of this integrated MN system as a simple, cost-effective, and minimally invasive solution for passive ISF sampling and subsequent biochemical analysis.