Coupling selective laser sintering and supercritical CO₂ foaming for 3D printed porous polyvinylidene fluoride with...

In this study, a facile strategy coupling selective laser sintering (SLS) and supercritical carbon dioxide (ScCO₂) foaming technology is proposed to prepare a three-dimensional porous polyvinylidene fluoride (PVDF) with an improved piezoelectric output. The effects of foaming conditions including temperature and pressure on foam morphology, crystallization behavior and piezoelectric properties have been systematically studied. It is found that indeed the mechanical stretching foaming process greatly improves the produced content up to 76.2% of the β-phase in PVDF. The piezoelectric output of the PVDF foam with the highest open-circuit voltage could go up to 8 V (4.5 times printed parts), which could light up 4 LED lights and charge 4.7 μF 50 V capacitor to 3.51 V in 275 s. This study provides a feasible approach to 3D porous material fabrication for achieving high-performance piezoelectric materials and demonstrates the promising potential of energy harvesters and smart sensors.