A High-Performance, Sensitive, Wearable Multifunctional Sensor Based on Rubber/CNT for Human Motion and Skin Temperature Detection.

Recently, flexible wearable electronic devices have attracted immense interest as an alternative for conventional rigid metallic conductors in personal healthcare monitoring, human motion detection, and sensory skins, owing to their intrinsic characteristics. However, the practical applications of most wearable sensors are generally limited by their poor stretchability and sensitivity, unsatisfactory strength, lower conductivity, and single sensory function. Here a hydrogen bond cross-linked network based on carboxylic styrene butadiene rubber (XSBR) and hydrophilic sericin (SS) non-covalently modified carbon nanotubes (CNTs) is rationally designed and then fabricated into multi-functional sensors. The resultant versatile sensors are able to detect both weak and large deformations, which owns a low detection limit of 1% strain, high stretchability up to 217%, superior strength of 12.58 MPa, high sensitivity with a gauge factor up to 25.98, high conductivity of 0.071 S m-1 , and lower percolation threshold of 0.504 wt%. Moreover, the prepared sensors also possess an impressively thermal response (0.01636 °C-1 ) and realize the application in the measurement of human body temperature. The multifunctional and scalable XSBR/SSCNT sensor with the integrated tracking capabilities of real-time and in situ physiological signals, providing a promising route to develop wearable artificial intelligence in human health and sporting applications.

Strengthened, Antibacterial, and Conductive Flexible Film for Humidity and Strain Sensors.

With the development of artificial intelligence, people are not satisfied with the traditional conductive materials and tend to focus on stretchable and flexible electronic systems. Flexible conductive rubbers have great potential applications in wearable strain sensors. However, the rapid propagation of bacteria during the use of wearable sensors may be an ineluctable threat to humans' health. Herein, a conductive rubber film is fabricated based on carboxylic styrene-butadiene rubber (XSBR), citric acid (CA), and silver nitrate (AgNO3) via a convenient approach, where Ag nanoparticles (Ag NPs) are in situ reduced without sintering at elevated temperatures. The resultant films exhibit many desirable and impressive features, such as strengthened mechanical properties, flexibility, and conductivity. More importantly, the Ag NP flexible conductive films exhibit excellent antibacterial activity against Escherichia coli (Gram-negative bacteria) and Staphylococcus aureus (Gram-positive bacteria), which have potential applications as flexible antibacterial materials to monitor movements of the human body in real time. Also, because of the hygroscopicity of CA, the resistance of our conductive film is sensitive to various humidities, which can be applied in the humidity sensor.