Comprehensive effects of isomeric doping on electrospun PVDF films: Towards smart wiper systems enabled by piezoelectric nanogenerators and machine learning

Abstract

Piezoelectric nanogenerators (PENG) face limitations due to the singularity of material doping strategies, hindering their ability to meet the requirements of complex application scenarios. Herein, isomerism of polyaniline (PANi) and halloysite nanotubes (HNT) were synthesized via oxidative polymerization to systematically explore the modulation mechanisms affecting the properties of electrospun PVDF films. The hybrid structure of PANi/HNT doping maintained the tensile strength (15.8 MPa) enhancement effect of HNT on the polymer matrix, while the high conductivity of PANi contributed to a denser surface morphology of the films. However, agglomeration persists, and the improvement in the piezoelectric properties of PVDF remains limited. In contrast, the encapsulated structure of PANi@HNT doping offered only a modest improvement in mechanical properties. However, improved compatibility with the matrix led to excellent filler dispersion, and the increased number of nucleation sites raised the β-phase content of PVDF to 91.71 %. The highly sensitive PENG exhibits an open-circuit voltage (V_OC) of 81 V and a short-circuit current (I_SC) of 8.36 μA. The smart wiper system, developed through integration with machine learning and microcontroller unit (MCU), achieves accurate rainfall recognition and real-time response, offering a novel approach for PENG applications in smart sensing.