Highly Stretchable Composite Conductive Fibers (SCCFs) and Their Applications.

Stretchable composite conductive fibers (SCCFs) exhibit remarkable conductivity, stretchability, breathability, and biocompatibility, making them ideal candidates for wearable electronics and bioelectronics. The exploitation of SCCFs in electronic devices requires a careful balance of many aspects, including material selection and process methodologies, to address the complex challenges associated with their electrical and mechanical properties. In this review, we elucidate the conductive mechanism of SCCFs and summarize strategies for integrating various conductors with stretchable fibers, emphasizing the primary challenges in fabricating highly conductive fibers. Furthermore, we explore the multifaceted applications of SCCFs-based frameworks in wearable electronic devices. This review aims to emphasize the significance of SCCFs and offers insights into their conductive mechanisms, material selection, manufacturing technologies, and performance improvement. Hopefully, it can guide the innovative development of SCCFs and broaden their application potential.

Highly Stable, Bending-Tolerant, and Sustainable Flexible Heater through a Scalable Papermaking Procedure.

Flexible electrothermal heaters have attracted abundant attention in recent years due to their wide applications, but their preparation with high efficiency remains a challenge. Here in this work, a highly stable and bending-tolerant flexible heater was fabricated with graphite nanosheets and cellulose fibers through a scalable papermaking procedure. Its electrothermal property can be enhanced by a hot-pressing treatment and introduction of cationic polyacrylamide (CPAM) during the papermaking protocol. The flexible heater may quickly reach its maximum temperature of 239.8 °C in around 1 min at a voltage of 9 V. The power density was up to 375.3 °C cm2 w-1. It appeared to have a high tolerance for bending deformation with various curvatures, and the temperature remained stable even under 100 bending with frequency of around 0.17 Hz. Over 100 alternatively heating and cooling cycles, it worked stably as well. It was proved to be used as wearable heating equipment, soft heaters, and aircraft deicing devices, suggesting its great prospect in the field of heat management.

A Flexible Multimodal Sensor That Detects Strain, Humidity, Temperature, and Pressure with Carbon Black and Reduced Graphene Oxide Hierarchical Composite on Paper.

Flexible sensors (FSs) are the key components of intelligent equipment and wearable devices, thus attracting increasing research interests in recent years. However, the preparation of multifunctional FS with good degradability in a natural environment is still challenging. In this work, we fabricated a flexible multimodal sensor that can detect multiple stimuli with only one device by spraying the mixture of carbon black (CB) and reduced graphene oxide (rGO) on a paper substrate. Scanning electron microscopy visualization indicated the CB particles absorbed on the surface of rGO, which then overlayered together, constructing a hierarchical structure. Benefiting from this unique structure, the obtained FS was demonstrated to have good sensitivity for strain, humidity, temperature, and pressure as well as multiple stimuli and was used to monitor human respirations as well as body motions, such as finger and elbow bending and head nodding. Besides, the sensor can be easily degraded in water being free of electronic pollution, but it also can be reused after the soaking-drying process, implying its reliability. This degradable and multimodal FS may find great potential in flexible electronics.