Highly sensitive flexible graphene pressure sensor based on indocalamus leaves’ microstructure

In recent years, high-performance flexible pressure sensors have attracted much attention due to their important application potential in intelligent robotics, wearable electronics, and electronic skin. Here, a wearable pressure sensor with high sensitivity in a large useable range is demonstrated. By utilizing indocalamus leaf as a template, the sensing layer of the sensor was prepared in the form of Graphene films with a bionic composite microstructure. Due to the hierarchical deformation of bionic composite microstructure, the sensor demonstrates high sensitivity and wide detection range at the same time. The sensitivity of sensor is 4.56 kPa−1 (5 Pa-20 kPa), 1.87 kPa−1 (20 Pa-100 kPa) and 0.70 kPa−1 (100 kPa-250 kPa). Therefore, it is not only sensitive to slight pressure as low as 5 Pa but also has a detection limit up to 250 kPa. At the same time, sensor has a short response time of 130 ms. After 1000 pressure cycles, the current change rate of the sensor can still reach 90% of the original. Meanwhile, the flexible pressure sensor could be used for monitoring human physiological signals, such as wrist pulse, voice recognition, and human activities, which shows a broad application prospect.