| 초록 |
Flexible piezoelectric energy harvesters have been considered as a powerful candidate to achieve self-powered electronic systems for environmental sensors and bioimplantable devices using the self-generated electrical energy. Therefore, many researchers have demonstrated high-performance flexible energy harvesters using the representative piezoelectric materials, which are Pb(Zr,Ti)O3 (PZT) and other lead-based piezoceramics, even for wearable and in vivo applications. Despite their high piezoelectric and ferroelectric properties, the lead-based piezoelectric ceramics should be utilized for ecological and biological applications due to their toxicity and non-biocompatibility resulting from the renowned inorganic poison, Pb (lead). In contrast to the lead-based piezoceramics, (K,Na)NbO3 (KNN)-based materials are the promising piezoceramics due to not only biocompatibility but also excellent piezoelectric characteristics with well-designed doping or alloying. Nevertheless, it is difficult to be deposited, densified, and sintered as a thin film because of the difficult control of alkaline elements. In this talk, I will introduce and report a KNN-based lead-free and high-performance flexible energy harvester on a plastic sheet fabricated by novel laser-lift off (LLO) technology and facile aerosol deposition (AD) method with proper Li doping. It showed the highest output performance among all previously reported lead-free flexible energy harvester, even similar to the lead-based flexible piezoelectric generators. Furthermore, we proved all types of biocompatibility conditions (i.e., in vitro, ex vivo, and in vivo) including not only cell viability and histology but also bioimplantation and ionic elusion. |
