Full‐Textile Wireless Flexible Humidity Sensor for Human Physiological Monitoring

Abstract

Textile-based electronic techniques that can in real-time and noncontact detect the respiration rate and respiratory arrest are highly desired for human health monitoring. Yarn-shaped humidity sensor is fabricated based on a sensitive fiber with relatively high specific surface area and abnormal cross-section. The response and recovery time of the yarnshaped humidity sensor is only 3.5 and 4 s, respectively, with little hysteresis, because of the hydrophobic property of these functional fibers and the grooves on the surface of the fibers, which is much faster than those of the commercial polyimide materials. Moreover, a batteryfree LC wireless testing system combined with the yarn-shaped sensor is fabricated, which is further successfully imbedded into the intelligent mask to detect human breath. Based on the detection of LC wireless testing system, the frequency of 50.25 MHz under the exhaled condition shifts to 50.86 MHz under the inhaled situation of humidity sensor. In essence, the functional yarns with proper structure, would be an excellent candidature to the yarn-shaped humidity sensor, in which there are good performance and wide application possibilities, eventually offering a facile method for the wireless detection of human physiological signals in the field of electronic fabrics.

Human Respiratory Monitoring Based on Schottky Resistance Humidity Sensors

“…[10][11][12][13]. Wearable electronic textile humidity sensors based on carbon nanotubes and composite fibers have also been developed [14,15]. The Schottky structure has been used extensively in photoelectric sensing, and Schottky structure humidity sensors for noncontact medical monitoring have been reported in recent years [16].…”

Effects of pH on High-Performance ZnO Resistive Humidity Sensors Using One-Step Synthesis

“…In recent years, humidity sensors have played an important role in the development of medical, food preservation, environmental monitoring, semiconductor, and other industries [1,2,3,4]. With the deepening of research, humidity sensors are required to meet special characteristics, such as high sensitivity, fast response/recovery speed, low hysteresis, and long-term stability [5,6,7].…”

The Evolution of Flexible Electronics: From Nature, Beyond Nature, and To Nature

“…[38][39][40][41] The self-healing ability, inspired by the spontaneous restorative feature of human skin, endow the flexible devices with self-repairing ability upon damages as well as enhancing their wearability. The environmental sensing ability, one of the most widely used functions in many flexible electronics devices to monitor atmosphere condition, are also derived from commonly existed nature signals, such as light, [42] humidity, [43][44][45] pH, [46] etc. For the flexible electronics, functionality integration with various powerful functionalities including self-powering, energy storage, sensing, mechanical deformability, etc., was rather essential to cater for more complicated condition in human-interactive devices, soft robots, medical devices, etc.…”