Skin Hydration Sensor for Customizable Electronic Textiles

This paper introduces the design and simulated operation of a capacitive hydration sensor for integration into textile-based electronics. The multilayer patch is composed of a textile layer and an attached series of serpentine-interdigitated electrodes. The model used for simulations incorporated this design onto a representative model of skin. The serpentine-interdigitated electrodes are electrodes for capacitive measurement of skin hydration. In this study, the capacitance change relative to skin hydration was simulated using finite element analysis. The simulation results suggest the fabric layer had little effect on the capacitance of the sensor. Furthermore, the frequency domain simulations indicated that the capacitance of the sensor decreased with increasing frequency, and the decrease in capacitance was more significant for the dry skin compared to the wet skin. Therefore, the variation in the capacitance value of the serpentine-interdigitated electrodes can be employed for continuous skin hydration detection.