Electromechanical Performance and Figure of Merit Optimization for Flexible Lead-Free PDMS–BaTiO3 Piezocomposites

High Resolution Image Download MS PowerPoint Slide In the modern era of the Internet of Things, the potential role of flexible piezoelectric generators (PEG) reflects the rapid increase in self-powered devices and wearable technologies. In this study, a casting process to elaborate the polydimethylsiloxane (PDMS)/barium titanate ( BaTiO 3 ) composite has been presented. The addition of 15 wt % BaTiO 3 microparticles into the PDMS polymer greatly enhances the piezoelectric coefficient ( d 31 = 24 pC N –1 ), leading to an increased output voltage of approximately 4 V under finger tapping force. The proposed flexible microgenerator yielded an excellent piezoelectric figure of merit ( FoM 31 = 13.1 × 10 –12 m 2 N –1 ), significantly enhancing successfully the energy-harvesting performance (power density of 35 nW/cm 2 ). Furthermore, the fabricated lead-free PEG exhibited an excellent flexibility figure of merit ( f FoM) due to the low young modulus values (Maximum E = 3.4 MPa). These results indicate efficient energy conversion and demonstrate a favorable balance between the flexibility and piezoelectric properties of the composite, highlighting its potential for a wide range of applications in self-powered wearable sensors able to collect different human motions in applications such as gesture tracking and finger motion detection.