Abstract
Monitoring skin health through parameters like skin hydration (SH) and transepidermal water loss (TEWL) is vital for diagnosing skin conditions and identifying disease factors. Conventional devices and survey-based methods often fail to deliver accurate diagnoses due to circadian rhythms of skin health data, limited measurement frequency, and patient subjectivity. Previous research has shown that prolonged device usage also causes sweat accumulation, compromising reliable monitoring. Here, we present a breathable skin health analyzer (BSA), a wearable device designed for prolonged use, capable of accurate, long-term measurement of SH and TEWL. The BSA addresses considerable obstacles in skin health monitoring by employing a breathable chamber and a bistable actuator that ensures both ventilation and consistent sensor contact with the skin. Validated through a 28-day clinical trial, the BSA and data processing algorithms demonstrated their effectiveness in providing reliable data by analyzing the correlation between particulate matter exposure and the skin barrier health. These results not only highlight the potential to improve the diagnosis and treatment of diseases but also show the possibility of contributing to individual environmental health impact assessments and translational studies.