Wireless and Flexible Skin Moisture and Temperature Sensor Sheets toward the Study of Thermoregulator Center

Abstract

A disorder in the thermoregulator center in a human body leads to some potential diseases such as fever and hyperthyroidism. To predict these diseases early, monitoring the health condition of the human body due to the influence of thermoregulation disorders is important. Although extensive works are performed on sweat‐rate detection by constructing microfluidic channels, skin‐moisture evaporation before sweating remains unknown. This work proposes a wireless and flexible sensor sheet to investigate the thermoregulatory responses of different people under cold stimulation and exercise by measuring the temperature and moisture variations on the finger skin. An integrated flexible sensor system consists of a ZnIn2S4 nanosheet‐based humidity sensor and carbon nanotube/SnO2 temperature sensor. The results exhibit distinct thermoregulation abilities of five volunteers. Interestingly, the sudden increase in finger moisture that results from the excitation by the sympathetic nerve is observed during the cold‐stimulus test. Although further studies are required to predict the potential diseases resulted from thermoregulation disorders in human body, this study provides a possibility of continuous and real‐time monitoring of thermoregulatory activities via skin moisture and temperature detection using a flexible sensor sheet.

Emerging wearable flexible sensors for sweat analysis

“…In the past decade, increasing advances in engineering design, materials science, and fabrication technologies have enabled the rapid development of wearable sensors [7][8][9], including sweat sensors. Compared with conventional quantitative analysis methods of sweat for clinical purposes that require on-site sweat collection, expensive equipment, and trained professionals [10], wearable sweat sensors can be directly attached onto the skin surface for real-time sweat collection and analysis [11].…”

Flexible Electronics and Devices as Human–Machine Interfaces for Medical Robotics

“…[224] In medical rehabilitation, temperature sensing is commonly used to monitor the body, which can be a reference for health. [225,226] In the field of medical rehabilitation, monitoring body temperature at different locations can reflect the body's state (both physiological and psychological) in real time. For example, the potential fatigue and psychological tension during the rehabilitation process can cause temperature variations due to sweat evaporation.…”

“…[ 224 ] In medical rehabilitation, temperature sensing is commonly used to monitor the body, which can be a reference for health. [ 225,226 ]…”

“…For example, the potential fatigue and psychological tension during the rehabilitation process can cause temperature variations due to sweat evaporation. [ 226 ] In addition, some disease‐induced disabilities have distinct thermal characteristics (either high or low) at the extremities due to abnormal blood circulation and metabolism state. For example, the foot temperature of some diabetic patients can be about 5 degrees Celsius higher than that of healthy people.…”

Review of Robot Skin: A Potential Enabler for Safe Collaboration, Immersive Teleoperation, and Affective Interaction of Future Collaborative Robots

“…Despite the above advancements in proximity and pressure sensing, temperature gradient detection capability is also required for material identification and object manipulation [168], [155]. Similar to pressure sensing, the transduction mechanism of temperature sensors is based on resistive materials [75], [169]- [174], capacitive materials [76], thermoelectric materials [175]- [177], iontronic materials [74], [77], [178], biomimetic materials [179], [180], and fiber-optic materials [181]. The key characteristics of recent representative temperature sensors based on the above materials are summarized in Table V.…”