Electrospinning fibrous membrane matrix ionic capacitive sensor for pressure value and distribution detection

Abstract

Considering the practical applications of capacitive sensors, electrical sensing fibrous membranes should own high mechanical strength, elasticity, sensitivity, thermal diffusivity and biocompatibility, listing the basic design and preparation demands via electrostatic spinning. Polyvinylidene fluoride (PVDF) fibrous membrane matrix pressure ionic capacitive sensors were prepared via electrostatic spinning. The addition and dissolution of polyvinylpyrrolidone (PVP) particles realized porous structures of PVDF fibrous membrane, providing silver particles (Ag) dependence matrix for conductive Ag-porous PVDF fibrous membrane of electrode layer. The PVDF matrix capacitive sensor was composed of sandwiching dielectric layer of PVDF fibrous membrane with ionic liquid (IL-PVDF) between two electrode layers. The construction of electrical double layers at the interfaces between electrode layer and dielectric layer significantly enhanced capacitance sensing properties. After encapsulating by pure PVDF fibrous membranes, PVDF fibrous membrane matrix ionic capacitive sensor exhibited excellent stability, sensitivity and durability in pressure loading range of 0–8 kPa for 5000 cyclic experiments，which was suitable for real-time detection of multiple physiological bending signals. Based on pressure sensing array construction, the values and distribution of static and dynamic loads were reflected accurately and intuitively, providing feasible methods for practical applications of functional fiber matrix sensors in fields of healthcare and human-machine interaction.