LAUSR

Summary Medical diagnosis often depends on the retrieval of a blood sample, which is an intrusive process involving physical trauma and often poses the risk of infection. This has led to the development of non-invasive alternatives often targeting biofluids such as saliva, sweat and tears as readily available sources of relevant biomarkers. Sweat is of particular interest in this regard due to its accessibility and composition. Monitoring changes in its electrolyte composition provides important information on the personal hydration status of athletes and certain clinical health conditions. This article reviews the recent advances, opportunities and challenges in the development of wearable sensors for monitoring electrolyte levels in real time.