Protrusion Microstructure-Induced Sensitivity Enhancement for Zinc Oxide–Carbon Nanotube Flexible Pressure Sensors

Carbon nanotubes (CNTs) have broad application prospects in flexible pressure sensors because of their superior mechanical and electrical performance. However, the pressure sensitivity of a pure CNT sensor needs to be enhanced. Herein, a zinc oxide–carbon nanotube (ZnO–CNT) sensor with a protrusion microstructure was prepared to improve the pressure sensitivity of a pure CNT sensor. The results show that the ZnO–CNT sensor achieves a higher pressure sensitivity (8.79 times) than that of the pure CNT sensor. In addition, the ZnO–CNT sensor achieves fast response (125.28 ms), good durability (over 6000 cycles), and a high upper detection limit (up to 422.22 kPa). The enhancement in sensitivity of the ZnO–CNT sensor is explained by the finite element simulation. Benefiting from these characteristics, the ZnO–CNT sensor is expected to be applied in human physiological signs and motion monitoring.