Microfluidic-electrochemical sweat patches for athletes: monitoring lactate, electrolytes, and hydration status

Clinical Snapshot

Key Findings

• P Value: Not applicable — narrative review without statistical testing

• Effect Size: No pooled effect size reported. Individual device performance metrics described qualitatively: enzymatic lactate sensors characterised by sensitivity, response time, and oxygen dependence; ion-selective electrodes assessed by Nernstian slope, drift, and biofouling susceptibility

• Primary Outcome: Narrative synthesis of analytical performance of microfluidic-electrochemical sweat patches for lactate (via lactate oxidase amperometry), sodium and potassium (via potentiometric ion-selective electrodes), and hydration biomarkers in athletes

• Nnt Or Sensitivity: No NNT, sensitivity, or specificity data pooled. The review notes the sweat-to-blood biomarker relationship is 'debated' and that validation protocols are not standardised across the literature, precluding reliable diagnostic accuracy estimates

• Confidence Interval: Not applicable — no meta-analytic synthesis performed

Clinical Application

Currently limited to research and high-performance sports science settings. Commercial-grade devices with regulatory clearance are not yet widely available. Key feasibility barriers identified include: long-term sensor stability (hours to days), skin adhesion under sweat and motion, scalable manufacturing, and absence of standardised sweat collection and calibration protocols. Wireless readout and multiplexed sensing are technically demonstrated but not clinically validated at scale. No TGA-cleared wearable sweat patch devices for lactate or electrolyte monitoring are currently listed on the ARTG for clinical use in Australia. The technology sits within the TGA's IVD regulatory framework as an emerging category. RACGP and Sports Medicine Australia guidelines do not currently incorporate wearable sweat biomarker monitoring into standard athlete care pathways. In the Australian context, heat stress and dehydration management are clinically significant given environmental conditions, and validated sweat monitoring could have meaningful application in occupational health (mining, defence, agriculture) as well as elite sport. PBS listing is not applicable at this stage. Australian Institute of Sport (AIS) research programs may be relevant early adopters pending regulatory maturation. Competitive and recreational athletes undergoing aerobic training or competition in whom real-time monitoring of metabolic fatigue (lactate), electrolyte balance (sodium, potassium), and hydration status is desired. Potential secondary applicability to clinical populations requiring non-invasive electrolyte monitoring (e.g., cystic fibrosis, heart failure, renal disease) though this is not the review's focus.

Abstract

Wearable biochemical sensing is shifting sports physiology from intermittent laboratory sampling toward continuous, in situ readouts during training and competition. This review analyzes skin conformal systems that integrate capillary driven fluid routing, flexible sensor arrays, and wireless readout to capture dynamic changes in eccrine secretions relevant to performance management. We compare microchannel layouts that enable controlled filling, time resolved sampling, and evaporation suppression, and we discuss how material selection governs comfort and analytical fidelity, highlighting tradeoffs among polydimethylsiloxane, polyurethane, and polyethylene terephthalate substrates and their compatibility with scalable fabrication. Manufacturing pathways are assessed from soft lithography to laser cutting, three dimensional printing, and roll to roll processing for high throughput multilayer assembly. For transduction, we summarize enzymatic amperometric schemes based on lactate oxidase with hydrogen peroxide detection, including sensitivity, response time, and oxygen dependence, and we contrast these with emerging non enzymatic catalysts. We then detail potentiometric ion selective electrodes for sodium and potassium, focusing on ion selective membrane chemistry, solid state reference electrodes, Nernstian response, and dominant error sources such as drift and biofouling. System integration challenges, including chemical and electrical cross talk in multiplexed layouts, are linked to microfluidic isolation strategies and multiplexed electronics. Finally, we appraise validation practice, emphasizing the debated sweat to blood relationship, the need for synchronized comparative protocols, and the role of data analytics and machine learning for personalization, drift compensation, and prediction of thermoregulatory strain. Remaining barriers include long term stability, adhesion under motion, manufacturability, and regulatory evidence requirements in real world settings. Across these topics, the review emphasizes technology-specific limitations, engineering translation metrics, and realistic breakthrough directions rather than treating wearable sweat patches as a mature plug-and-play platform.

References

1. 1.Liu, H., & Lin, W. (2026). Microfluidic-electrochemical sweat patches for athletes: monitoring lactate, electrolytes, and hydration status. Analytical Methods: Advancing Methods and Applications. https://doi.org/10.1039/d6ay00936k