Sustainable PLA Innovations for Recyclable Piezoelectric Transducers and Harvesters

Piezoelectric transducers play a crucial role in energy harvesting and sensing applications within the automotive industry. Vibrational Piezoelectric Energy Harvesters (VPEH) effectively harness dynamic mechanical inputs such as high-frequency vibrations in vehicles. Traditional transducers rely on lead-based ceramics, such as lead zirconate titanate (PZT), and polyvinylidene fluoride (PVDF), which pose environmental and health risks. This study explores biosourced and recyclable alternatives, focusing on polylactic acid (PLA) due to its biobased nature, ease of processing, and comparable piezoelectric properties. A novel VPEH prototype, constructed primarily from PLA, was developed with enhanced piezoelectric properties (13 pC/N), direct ink-printed silver electrodes on PLA substrate, and 3D-printed PLA cantilever beams optimized for vibrational energy harvesting at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\sim 30 \text{Hz}$</tex> resonance frequency. The VPEH prototype demonstrated thermal stability, cost-effective manufacturability, and shows a potential to generate power (higher than <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$10 \mu W$</tex>) for automotive sensor applications.