Pressure and Temperature Dual-Parameter Sensor Based on Natural Wood for Portable Health-Monitoring Devices

Abstract

Flexible wearable sensors have been widely used in medical detection. In the clinic, pulse and body temperature are two critical vital signs. Continuous and real-time monitoring is of great significance to human health. Herein, a wearable sensor based on a wood sponge is designed to detect human biological signals fabricated by chemical treatment and freeze-drying. After decorating the porous sponge with single-walled carbon nanotubes (SWCNTs) and poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), the sensor can precisely detect the pressure with a sensitivity of 1.05 kPa–1 in the low-pressure region (0–10 kPa) and a response time of 20 ms as well as a the temperature with a minimal detection limit of 0.5 K and a response time of 0.8 s. Based on the principles of piezoresistive and thermoelectricity, independent voltage and current signals can be generated and collected under simultaneous pressure–temperature stimuli. Through tests of volunteers, our sensor can accurately capture the pulse and skin temperature of different arteries and identify changes in signs before and after fever. This practical and sustainable strategy promotes the development of new-generation portable medical devices.