Nanoenergy and Biosystem Lab

 Self-powered implantable medical devices based on nanogenerators

Miniaturization is one of the trends in developing new implantable medical devices. It is extremely difficult to deal with the ambivalence in miniaturization, between the long-term energy supply and growth of energy consumption caused by multi-functionalization. Nanogenerators are prone to be the key of dealing with the in vivo energy supply of implantable medical devices.
Nanogenerator was invented by Prof. Zhong Lin Wang in 2006 for the first time. It refer to a micro/nano device. The device can transform random mechanical energy to electricity using piezoelectric ZnO nanowire arrays. Including Piezoelectric nanogenerator (PENG), there are two other kinds of nanogenerators (NGs): Triboelectric nanogenerator (TENG) and Hybrid nanogenerator & Piezo-triboelectric nanogenerator (PTNG). The different kinds of NGs can convert irregular mechanical energy into electricity in various environment and are extremely appropriate for scavenging random energy for wide applications.
Our group stared to investigate implantable nanogenerators since 2007. We demonstrated the first in vivo mechanical energy harvester and devices. Meanwhile, the flexible nanogenerators based on ZnO NWs have successfully harvested the mechanical energy inside a live animal in the world, such as breathing and heartbeat (Adv. Mater. 2010, 22, 2534–2537). We also made significant progress in the application of implantable nanogenerators during 2014 to 2016: (1) A great promotion of in vivo power generation have been achieved. The output voltage and current reached up to 14v and 5μA, respectively (ACS Nano 2016, 10, 6510−6518). (2) Harvested the mechanical energy from a live animal and stored the electric energy in a capacitor. The collected electricity was used to activate pacemaker prototype and control the frequency of heartbeat for the first time (Adv. Mater. 2014, 26, 5851–5856; Adv. Mater. 2016, 28, 846–852). (3) Real-time acquisition and wireless transmission of self-powered cardiac monitoring data was demonstrated for the first time. It showed broad clinical applications of implantable self-powered medical systems for disease detection and health care (ACS Nano 2016, Nano Lett. 2016, 16, 6042−6051).
These works are concentrated on live-powered implantable medical devices. The nanogenerators can convert the mechanical energy from human motion into electricity and drive the implanted long-term self-powered medical devices or biosensors.

　　　 　　　 基于纳米发电机的植入式电子医疗器件

　　植入式电子医疗器件的两大发展趋势，其中之一是微型化，而微型化最大的困难就是能源的长期供给与功能复杂化之后能耗不断升高之间的矛盾。纳米发电机（Nanogenerator）有可能成为解决植入式电子医疗器件在体能源供给问题的关键。
　　纳米发电机是王中林院士于2006年最早提出来的，是指利用压电氧化锌纳米线阵列将随机的机械能转化为电能的微纳器件。现在除了压电纳米发电机（Piezoelectric nanogenerator, PENG），还有摩擦电纳米发电机（Triboelectric nanogenerator, TENG）和复合压电和摩擦电的复合纳米发电机（Hybrid nanogenerator & Piezo-triboelectric nanogenerator, PTNG），可以在更加广阔的应用领域将无规则的机械能转换为电能，对于收集环境中的随机能量来说是非常理想的。
　　我们课题组从07年开始研制植入式纳米发电机（Implantable nanogenerators），进行体内机械能的收集和转换，并在国际上首先采用单根氧化锌纳米线的柔性纳米发电机实现了活体动物呼吸运动和心脏搏动的机械能收集（Adv. Mater. 2010, 22, 2534–2537），并于2014-2016年期间在植入式纳米发电机领域取得多项突破：1）植入式纳米发电机的体内发电功率有巨大提升，电压和电流分别达到14 V和5μA（ACS Nano 2016, 10, 6510−6518）；2）第一次实现了体内机械能的收集与存储，并可利用收集的电能驱动心脏起搏器原型机控制动物心脏跳动频率（Adv. Mater. 2014, 26, 5851–5856；Adv. Mater. 2016, 28, 846–852），也可以驱动红外器件促进骨愈合和牙齿修复（ACS Nano 2015,9, 8, 7867-7873）；3）第一次实现了自驱动心脏监测数据的实时采集和无线传输，验证了植入式自驱动医疗监护系统的临床应用（ACS Nano 2016, 10, 6510−6518; Nano Lett. 2016, 16, 6042−6051）。
　　本研究方向的目标是生命驱动的纳米医疗电子器件：通过纳米发电机等机械能收集器件，将人体运动的能量转换为电能，驱动植入式电子医疗器件长期、稳定的在体工作，实现人体自供能的医疗和传感。