LiNbO3 films – A low-cost alternative lead-free piezoelectric material for vibrational energy harvesters

Lead-free lithium niobate (LiNbO3) piezoelectric transducer is considered as a substitute to lead-based solutions for vibrational energy scavenging applications. Taking into account the much lower dielectric constant of LiNbO3 crystal compared conventional piezoceramics (for instance PZT), we implement, in global optimization approach, thick single film on silicon substrate with optimized clamped capacitance better impedance-matching conditions. We design cantilever based (YXl)/36° cut, enhancing output voltage achieve performance compatible harvesting device standards. For bending first resonant frequency 1.14 kHz, an power up 380 ?W achieved, yielding density 8.26 ?W.mm?2, therefore comparable and -free harvesters, while featuring widely used material well-established production process (hence lowering cost instance). The capabilities allows starting sensor node (from zero initial conditions) after 9 s only then maintaining possibility sending data every 2 (each transmission event consuming approximately 420 ?J) under continuous excitation.