High Performance Strain Sensor Based on Carbon Black/Graphene/Ecoflex for Human Health Monitoring and Vibration Signal Detection

In recent years, there has been a significant surge of interest in flexible strain sensors within the domains of wearable electronics and human–computer interaction. However, as these fields continue to advance rapidly, there is an urgent need to improve the comprehensive performance of flexible strain sensors including sensitivity, sensing range, response speed, and durability. In this study, we address this issue by transferring carbon black/graphene (CB/Gr) conductive nanocomposites onto the surface of an Ecoflex flexible substrate, which has been pretreated using sandpaper to enhance adhesion. The resulting flexible strain sensor exhibits high sensitivity, with a gauge factor of 51.4, while offering a wide sensing range of 100%. Notably, this sensor demonstrates high performance across various aspects, including a fast response time (60 ms) and excellent durability (up to 4000 stretching–releasing cycles). The versatility of this sensor is evident in its ability to effectively monitor both small strain activities, such as speech recognition, and larger strain activities, such as elbow bending. Moreover, the sensor has demonstrated outstanding performance in various application scenarios, including human health and motion condition monitoring as well as acoustic wave and vibration signals detection. Consequently, this highlights the sensor's remarkable adaptability and substantial potential for wide-range applications in these domains.