Ultrahigh Sensitive Au-Doped Silicon Nanomembrane Based Wearable Sensor Arrays for Continuous Skin Temperature Monitoring with High Precision

Monitoring the body temperature with high accuracy provides a fast, facile, yet powerful route about the human body in a wide range of health information standards. Here, the first ever ultrasensitive and stretchable gold-doped silicon nanomembrane (Au-doped SiNM) epidermal temperature sensor array is introduced. The ultrasensitivity is achieved by shifting freeze-out region to intrinsic region in carrier density and modulation of fermi energy level of p-type SiNM through the development of a novel gold-doping strategy. The Au-doped SiNM is readily transferred onto an ultrathin polymer layer with a well-designed serpentine mesh structure, capable of being utilized as an epidermal temperature sensor array. Measurements in vivo and in vitro show temperature coefficient of resistance as high as −37270.72 ppm °C⁻¹, 22 times higher than existing metal-based temperature sensors with similar structures, and one of the highest thermal sensitivity among the inorganic material based temperature sensors. Applications in the continuous monitoring of body temperature and respiration rate during exercising are demonstrated with a successful capture of information. This work lays a foundation for monitoring body temperature, potentially useful for precision diagnosis (e.g., continuous monitoring body temperature in coronavirus disease 2019 cases) and management of disease relevance to body temperature in healthcare.