Fig. 4: Demonstration of the BSA.

a An optical image of the unencapsulated device. b Diagram of the sensor operation scenario. c Illustration of the ventilation and measurement mode of breathable chamber by the actuator. d Comparison of the SH increase in long-term monitoring between non breathable patch-type SH sensor and our device. e Graph of the impact of micro-climate on TEWL measurement in our device during long-term monitoring f Measurement of SH and TEWL using the BSA during a day in daily life. g Illustration of when clinically outliers occur. h Ground truth graph of outlier and data when using humidity and humidity difference as features i Clustering graph of outlier and data when using humidity and humidity difference as features j An optical image of the device worn on non-lesional site near the lesional skin. k, l Comparison of the correlation between SH and TEWL for both atopic dermatitis patients and normal subjects. Statistical significance was assessed using two-sided Pearson’s correlation analysis.