Flexible PANI/Lotus Stemmed Fiber Sensor for Bifunctional Sensing of Physical and Chemical Stimuli

Abstract In recent times, high‐performance flexible sensors that can be fabricated environmentally friendly and low‐costly have received considerable attention owing to their potential applications in wearable health monitoring. The combination of biocompatibility, degradability, and recyclability between the substrate and sensor layer remains a challenge. Here, a highly sensitive multifunctional sensor is developed using a polyaniline (PANI)‐coated lotus stem fabric (PANI/LSF) for body physical and chemical stimuli in a simple way. The lotus stem fabric has excellent breathability, skin compatibility, and lightweight as a flexible substrate. Its high sensitivity at low pressure is experimentally verified, which can reach 0.3 kPa −1 in the 0–1.5 kPa range. In addition, the sensor has low detection limitation and good linearity of response to water molecules and short response and recovery times for water in N 2 or normal atmosphere at the range of 3.7–70.5% relative humidity (RH) and 19.6–66.8% RH, respectively. This can be successfully used in the recognition of various breathing behaviors. Therefore, the study has developed a breathable and skin‐friendly bifunctional sensor based on PANI and natural fabrics, which has great potential for application in human health care.