| 초록 |
Energy harvesting systems based on triboelectric nanomaterials are in great demand, as they can provide routes for the development of self-powered devices which are highly flexible, stretchable, mechanically durable, and can be used in a wide range of applications. Our recent research interest mainly focuses on the fabrication of high-performance triboelectric nanogenerators (TENGs) based on various kinds of nanomaterials. Flexible TENGs exhibit good performances and are easy to integrate which make it the perfect candidate for many applications, and therefore crucial to develop. In this presentation, I firstly introduce the fundamentals and possible device applications of TENGs, including their basic operation modes. Then the different improvement parameters will be discussed. As main topics, I will report transcutaneous ultrasound energy harvesting using triboelectric technology. Implantable medical devices (IMDs) are designed to perform or augment the functions of existing organs by using monitoring, measuring, processing units, and the actuation control. Conventional IMDs are powered with primary batteries that require frequent surgeries for maintenance and replacement. Therefore, IMDs require a new reliable and safe powering system to avoid the need for frequent surgeries. Recently my group demonstrated that ultrasound was used to deliver mechanical energy through skin and liquids and demonstrated that a thin inplantable vibrating triboelectric nanogenerator (TENG) is able to effectively harvest it. Ultrasound TENG (US-TENG) was triggered with an applied 20-kHz ultrasound at 3 W/cm2 reaching 9.71 V(root mean square [RMS]) and 427 ARMS. The measured output current was enhanced two orders of magnitude compared with conventional TENGs, with a similar level of surface charge density, triggered in low-frequency mechanical environments. Interestingly, to experimentally simulate clinical conditions closer to human in the laboratory, we inserted US-TENG under porcine tissue, showing that it fully charged a rechargeable Li-ion battery having a capacity of 0.7 mAh. As the second topic, I will deal with our very recent demonstration of a commercial coin battery-sized high-performance inertia-driven TENG (I-TENG) based on body motion and gravity. In a preclinical test, we demonstrate that the encapsulated device successfully harvested energy using real-time output voltage data monitored via a Bluetooth low-energy information-transmitting system. Details will be presented in the conference site. Finally the presenter will report a self-powered disinfection system for the rapid disinfection of air-transmitted bacteria and viruses based on a highly efficient nanowire-assisted electroporation mechanism powered by vibration-driven TENGs that harvest mechanical vibration energy. |
