Enabling Lightweight Piezoelectric Sensing Composites Through Polyvinylidene Fluoride‐Coated Hollow Microparticles

Lightweight and multifunctional polymer composites are widely used in aerospace, automotive, and sensing applications. Piezoelectric materials enable the conversion between mechanical loads and electrical signals, which is critical in energy harvesting and sensing devices. However, limitations in the density and brittleness of piezoelectric materials exist and motivate development of advanced lightweight deformable composites. This study utilized polyvinylidene fluoride (PVDF)‐coated hollow glass microspheres (HGMs) as hybrid fillers to enable lightweight and sensing functionality in elastomer‐based composites. The HGMs were initially coated with PVDF using a bladeless mixing process followed by ultrasonication to ensure uniform coating. The coated microparticles were then integrated into a polydimethylsiloxane (PDMS) matrix and 3D‐printed. Electromechanical experiments, including cyclic compressive testing and dynamic demonstrations, revealed enhanced mechanical energy absorption and improved piezoelectric sensing performance. The soft composites exhibited a density reduction of up to 47%, and the 15 wt% PDMS–PVDF‐coated HGM composite achieved the highest piezoelectric voltage coefficient of 34.9 ± 1.9 mV m N −1 , approximately five times that of the PDMS–PVDF control without using the HGMs. The composites also exhibited filler‐dependent thermal properties. Drop‐impact and blast tests demonstrated observable electrical responses under dynamic loading. This suggests potential for the hybrid composites in lightweight sensing applications.