Flexible and High Performance Piezoresistive Pressure Sensors Based on Hierarchical Flower-Shaped SnSe2 Nanoplates

Flexible piezoresistive pressure sensors featuring high sensitivity, wide operating pressure range, and short response time are required urgently due to the rapid development of smart devices and artificial intelligence. Herein, a high-performance flexible piezoresistive pressure sensor based on naturally formed hierarchical flower-shaped SnSe2 nanoplates and conical frustum-like structured polydimethylsiloxane (PDMS) is demonstrated. The micropatterned PDMS/Au and SnSe2 nanoplates/Au interdigital electrodes are exploited as the top and down part of the sensor, respectively. Benefiting from abundant contact sites and sufficient roughness provided by the SnSe2 nanoplates, the proposed sensing devices exhibit significantly enhanced sensitivity as high as 433.22 kPa–1 when compared with conventional configuration (planar Au film as the bottom interdigital electrodes). The resulting pressure sensor (PDMS/Au/Au/SnSe2) also presents wide operating pressure range (0–38.4 kPa), lower limit of detection (∼0.82 Pa), fast response time (∼90 μs), and long-term cycle stability (>4000 cycles). Therefore, it shows a great potential in various applications, such as the detection of the magnitude and distribution of the loaded pressure, as well as the monitoring of the human physiological signals.