Temperature/Pressure Dual-Mode Flexible Sensors: PP Nonwoven-Based and Low-Temperature Polymerized with Pyrrole

In recent years, flexible wearable sensors received significant attention from academia. Most sensors feature a single mode. Consequently, the production of wearable multimode flexible sensors that possess characteristics of flexibility, multimodal, and sensitivity remains a challenge. In this study, a fabric-based dual-mode flexible sensor is proposed. A polypropylene (PP) nonwoven fabric is first modified using polydopamine, impregnated with carbon ink, and low-temperature polymerized with pyrrole. Although the resulting sensors can detect stimuli from temperature and pressure, they also exhibit certain characteristics, such as lightweight, softness, and air permeability. Test results indicate that the flexible sensors efficiently function in detecting temperature and pressure, showing good stability. Specifically, the sensors exhibit adequate abilities in measuring and distinguishing two stimuli with a maximal temperature sensitivity coefficient of 0.447% degrees C-1 and sensitivity of 0.228 kPa-1 at a pressure zone of 0-45 kPa. The test results prove that dual-mode sensors demonstrate more advantages than single-mode ones. Therefore, the proposed sensors are a valuable reference for wearable equipment in the sports and health hygiene fields.