Electro-Assisted 3D Printing Multi-Layer PVDF/CaCl2 Composite Films and Sensors

Polyvinylidene fluoride (PVDF) films are widely used in sensors for their wide response frequency, good flexibility, low acoustic impedance, and chemical stability. In this work, PVDF/CaCl2 piezoelectric films were prepared by an electro-assisted 3D printing method and used to form a multi-layer composite film sensor. The study found that the addition of CaCl2 can effectively increase the beta-phase content in the PVDF film and improve the piezoelectric and dielectric properties of the PVDF composite film sensors. When the content of CaCl2 is 0.15 wt.%, the beta-phase content of the PVDF/CaCl2 composite film can reach the highest value of up to 48.47%, and the output voltage response of the sensor is 0.62 V at an input frequency of 10 Hz, 10 V voltage. The output voltage of PVDF composite film sensor with two and three layers is 1.306 and 1.693 times that of a single layer, respectively. The sensitivity of the multi-layer sensors has also been greatly improved.