Multifunctional Lightweight Polymer-based Hybrid Composites for Piezoelectric Sensing

Abstract

Lightweight and multifunctional polymer composites are widely used in aerospace, automotive, and biomedical applications. Piezoelectric materials enable the conversion between mechanical loads and electrical signals, which is critical for sensing applications; however, conventional piezoelectric materials are often limited by high density and brittleness. To address these limitations, polyvinylidene fluoride (PVDF)-coated hollow glass microspheres (HGMs) were used as a hybrid filler to introduce lightweight and electromechanical functionality into an elastomeric system. The HGMs were coated with PVDF using a high-power bladeless mixing process followed by ultrasonication to promote uniform surface coverage, then integrated into a polydimethylsiloxane (PDMS) matrix and processed via direct ink writing (DIW). The resulting composites exhibited a tunable reduction in density of up to two-fold, enhanced specific energy absorption, and improved voltage output under mechanical loading. Electromechanical testing demonstrated up to four-fold improvement in response compared to PDMS, with performance dependent on filler content and microstructural interactions. Thermal and rheological behavior further supported the tunability and printability of the system. A proof-of-concept buckling structure demonstrated measurable voltage generation under flow-induced deformation, highlighting the potential of these composites for soft sensing applications.