Development of a flexible and highly sensitive pressure sensor based on an aramid nanofiber-reinforced bacterial cellulose nanocomposite membrane

Wearable electronic sensors, especially piezoresistive pressure sensors, have attracted tremendous attention due to their portability, flexibility, and high sensitivity to slight changes in pressure. However, these sensors suffer from fabrication procedures as well as poor mechanical properties, pressure sensitivity. Herein, an aramid nanofiber (ANF)-reinforced bacterial cellulose (BC) nanocomposite membrane (ANFs@BC) was prepared by a simple vacuum-filtration self-assembly process. Compared to the untreated BC, the tensile strength of the resulting ANFs@BC increased from 36.3 to 58.3 MPa, corresponding to a 60.6% increase, which indicated that the ANFs reinforced the structure of the BC membrane. The flexible and strong ANFs@BC was further modified by silver nanowires (Ag NWs) to prepare the Ag/ANFs@BC, which was used as the pressure sensor. The prepared pressure sensor exhibited suitable antibacterial properties, high pressure sensitivity and remarkable long-term stability without any distinct decline in sensitivity, after a constant applied pressure of 5 kPa for 6000s. When being applied to the human body, the pressure sensor was capable of accurately recognizing different mechanical stimuli, which highlighted the promising potential of the sensor for use in human motion monitoring. This work provided a novel and efficient pathway to prepare the ANFs@BC with powerful mechanical properties. Besides, the Ag/ANFs@BC as the pressure sensor exhibited great value for use in wearable electronics.