2026 · Analytical sciences : the international journal of the Japan Society for Analytical Chemistry · paywalled
Microfluidic valves for wearable sweat analysis: a review
Tang et al.
The finding, in our words
This review of microfluidic valves for wearable sweat sensors identifies five valve types, capillary, Tesla, mechanical, stimuli-responsive and electro-actuated, and highlights unresolved challenges including variable sweat rates, device deformation during wear, limited reusability and material instability. Addressing these is essential for reliable long-term sweat monitoring outside clinics.
A paraphrase to the Library’s standard, never the abstract. The source is one link away and is always the authority.
This review establishes that microsampling across blood, saliva, urine and stool matrices offers validated workflows and regulatory recognition for human biomonitoring comparable to conventional methods. It finds that these decentralised approaches enhance participant acceptability and enable screening in remote or low-resource settings.
This narrative review finds that saliva is best suited to repeated neuroendocrine and metabolic measurements during exercise, sweat is most mature for electrolyte and sweat-rate monitoring with wearable compatibility, and exhaled breath offers access to volatile metabolism but remains instrumentally demanding. Each matrix requires matching to a defined clinical or exercise question with matrix-specific validation before translational use.
The authors developed a skin-conformal wearable electrochemical sensor that passively collects sweat and simultaneously measures creatine and lactate in real time, using covalent organic frameworks to stabilise the enzymes. In preliminary human studies with healthy individuals and chronic liver disease patients, the platform tracked dynamic changes in these sweat biomarkers, suggesting a route to non-invasive continuous monitoring of liver metabolic function.
Zhao et al., Advanced materials (paywalled) · source ↗
Warehouse workers frequently presented with concentrated urine pre- and post-shift, and a greater within-shift worsening of urine colour was associated with higher wearable-derived ergonomic risk movement counts. The study demonstrates that self-collected urine samples combined with wearable sensor data can remotely identify hydration-related injury risk in occupational settings.
Agostinelli et al., Frontiers in public health (paywalled) · source ↗
Wearable biochemical monitoring requires a complete measurement chain that integrates quality-controlled biofluid sampling, sensor fusion and metadata capture to convert raw sensor outputs into clinically valid digital biomarkers.