Integrated smart diaper for self-pumping urine drainage and comfortable on-site electroanalysis

Wearable sensor technology enables personalized health management by continuously monitoring physiological status. Among various biofluids, urine is particularly valuable for non-invasive diagnostics due to its rich biochemical content, making it ideal for real-time and on-site health monitoring. However, conventional urine analysis typically requires hospital-based facilities and is not suitable for daily tracking, especially for infants and patients with incontinence. In this work, we present an integrated smart diaper that enables autonomous urine collection and on-site analysis. The device comprises a Janus fabric layer, a superabsorbent core, and an electrochemical sensing module. The Janus fabric facilitates one-way, self-pumping urine transport from the skin-facing hydrophobic side to the hydrophilic sensing interface, effectively preventing backflow, keeping the skin dry, and improving comfort (approximately 2.6 °C reduction in temperature decrease and 8.1 % reduction in humidity increase) compared to common diapers in the market. As urine contacts the electrode array, it triggers electrochemical reactions for the selective and sensitive detection of key biomarkers, including glucose, uric acid (UA), and hydrogen ions. Then the sensor data is wirelessly transmitted to a smartphone via Bluetooth for real-time health assessment. The limit of detection (LOD) of the sensors is 0.244 mM for glucose and 21.4 μM for UA, and the sensitivity of the pH sensor is −58.25 mV/pH. This user-friendly point-of-care (POC) system offers an effective solution for continuous health monitoring and early disease detection in vulnerable populations such as infants and individuals with incontinence.