Self‐Healing Hydrogels as Flexible Sensor for Human Motion Monitoring

Abstract

Self-healing hydrogels were prepared by mixing the difunctionalized polyethylene glycol (DF-PEG) and chitosan (CS) in water. Due to the formation of Schiff base bond between DF-PEG and CS, the gelation could be realized in several seconds. Determined by the SEM showed that the hydrogel was composed of porous network structure. The dynamic formation and dissociation of Schiff base bond (À C=NÀ ) between the aldehyde group of DF-PEG and amino group of CS initiated the excellent self-healing property and reversible pH responsivity of hydrogels. Additionally, the hydrogels had excellent ductility and toughness with the fracture strain and stress of 88.2 % and 12.1 kPa. The hydrogels exhibited excellent strain sensing performance, which can be fabricated as the flexible sensor for real-time monitoring the large and delicate human motions. As a result, it is expected that the obtained self-healing hydrogels will broaden the application of gels in wearable electronics.

Tough Adhesive, Antifreezing, and Antidrying Natural Globulin-Based Organohydrogels for Strain Sensors

“…The linearity was calculated to be R 2 = 0.985. Compared with other resistive-type strain sensors, the PDMS-encapsulated BSA/PAAm OHG sensor showed a better linear behavior. − The sensor also showed a good work range and sensitivity performance. To ensure the stable operation of the sensor, we tested it in the 0–100% working range.…”

An Ultra‐Sensitive Flexible Resistive Sensor with Double Strain Layer and Crack Inspired by the Physical Structure of Human Epidermis: Design, Fabrication, and Cuffless Blood Pressure Monitoring Application

“…[1] Flexible sensors have the advantages of being lightweight and having good flexibility, [2][3][4][5][6] and are often researched in wearable devices to detect human movement and monitor physiological parameters. [7][8][9][10][11][12][13][14][15][16] Flexible sensors can be divided into resistive, [17][18][19] capacitive, [20][21][22] piezoelectric, [23][24][25] and triboelectric [26][27][28] according to their sensing principles. The working principle of the resistive type is based on the piezoresistive effect or strain effect.…”

Thermoelectric Hydrogel Electronic Skin for Passive Multimodal Physiological Perception

“…Wearable devices based on flexible electronic materials have broad application prospects in electronic skins, − intelligent healthcare monitoring, − energy harvesting, − and human-computer interactions. , The flexible and stretchable electronic devices that mimic the properties of human skin, allowing for seamless integration with the body and enabling real-time monitoring of various physiological parameters (such as body temperature, pulse, and sweat), are gradually being developed. − By detection and analysis of these bioelectrical signals, various diseases can be effectively diagnosed and treated. However, soft wearable devices are mechanically weak and may inevitably be susceptible to mechanical damage such as external friction, twisting, tearing, and compression in practical applications, resulting in a shortened service life. − In addition, they have two other major drawbacks, including being powered by an external power supply and a complex manufacturing process.…”