Self-powered wearable reverse iontophoresis system for interstitial fluid lactate extraction and detection

To address the issues of power source and invasiveness of interstitial fluid lactate monitoring, a self-powered, wearable reverse iontophoresis system (TENG-RIS) driven by a triboelectric nanogenerator (TENG) has been proposed for the extraction and detection of lactate from interstitial fluid. The TENG-RIS harvests biomechanical energy to drive reverse iontophoresis, enabling transdermal lactate extraction, which is visually detected by a colorimetric lactate sensor. In vitro tests using a Franz cell showed that the TENG-RIS achieved efficient lactate extraction, while in vivo experiments on mice indicated successful detection of lactate level changes following exercise without causing skin damage. Biocompatibility assessments further confirmed that TENG-RIS did not induce inflammation or tissue damage. These findings demonstrate that TENG-RIS provides a feasible, noninvasive, and biocompatible solution for continuous monitoring of lactate and other potential biomarkers in interstitial fluid.