| 초록 |
Low output current represents a critical challenge that has interrupted the use of triboelectric nanogenerators (TENGs) in a wide range of applications as sustainable power sources. Many approaches (e.g., operation at high frequency, parallel stacks of individual devices, and hybridization with other energy harvesters) remain limited in solving the challenge of low output current from TENGs. As the fist issue, I will present a nanocomposite material system having a superior surface charge density as a triboelectric active material. The nanocomposite material consists of a high dielectric ceramic material, BTO, showing great charge-trapping capability, together with a ferroelectric copolymer matrix, P(VDF-TrFE), with electrically-manipulated polarization with strong triboelectric charge transfer characteristics. We successfully acheived boosting power-generating performance for 1,130 V of output voltage and 1.5 mA of output current with this ferroelectric composite-based TENG, under 6 kgf of pushing force at 5 Hz. As the second topic, I will introduce a new strategy of adding electrolytes with asymmetric ion pairing to polymer friction layers of TENGs in order to enhance their triboelectric property. Indeed, KPFM measurements show that an addition of H3PO4, an electrolyte with more cations than anions, to PVA can make it one of the most negative triboelectric material; whereas, an addition of CaCl2, an electrolyte with more anions than cations, to PVA can make it one of the most positive triboelectric material. Furthermore, the TENGs based on such solid polymer electrolytes (SPEs) produce significantly higher power output than typical metal-polymer TENGs. Due to these unique features, SPEs are a promising triboelectric material for realizing high performance TENGs for self-powered small electronics. The recent research and design efforts for enhancing power generation performance of nanogenerators to realize self powering of portable and wearable sensors and electronics will also be discussed in this talk. |
