Implantable nanogenerator (i-NG) has shown great promises for enabling self-powered implantable medical devices (IMDs). One essential requirement for practical i-NG applications is its long-term bio-compatibility and bio-safety. This paper presents a systematic study of polydimethylsiloxane (PDMS) and PDMS/Parylene-C packaged polyvinylidene fluoride (PVDF) NGs implanted inside female ICR (Institute of Cancer Research) mice for up to six months. The PVDF NG had a stable in vitro output of 0.3 V when bended for 7200 cycles and an in vivo output of 0.1 V under stretching. Multiple advanced imaging techniques, including computed tomography (CT), ultrasound, and photoacoustic were used to characterize the embedded i-NGs in vivo. The i-NGs kept excellent adhesion to the adjacent muscle surface, and exhibited stable electrical output during the entire examine period. No signs of toxicity or incompatibility were observed from the surrounding tissues, as well as from the whole body functions by pathological analyses and blood and serum test. The PDMS package was also able to effectively insulate the i-NG in biological environment with negligible stray currents at a pA scale. This series of in-vivo and in-vitro studies confirmed the biological feasibility of using i-NG in vivo for biomechanical energy harvesting.

植入式纳米发电机 (i-NG) 在实现自供电植入式医疗设备 (IMD) 方面展现出了巨大的前景。i-NG实际应用的一项基本要求是其长期的生物相容性和生物安全性。本文介绍了一项将聚二甲基硅氧烷 (PDMS) 和 PDMS/聚对二甲苯-C 封装的聚偏二氟乙烯 (PVDF) NG 植入雌性 ICR（癌症研究所）小鼠体内长达六个月的系统研究。当弯曲 7200 次循环时， PVDF NG 的体外输出稳定为 0.3 V，拉伸时的体内输出为 0.1 V。使用多种先进的成像技术，包括计算机断层扫描 (CT)、超声和光声来表征体内嵌入的 i-NG 。i-NGs 与邻近肌肉表面保持良好的粘附力，并在整个检查期间表现出稳定的电输出。通过病理分析和血液和血清检测，周围组织以及全身功能均未观察到毒性或不相容的迹象。PDMS 包还能够有效地隔离生物环境中的 i-NG，并且 pA 级的杂散电流可以忽略不计。这一系列的体内和体外研究证实了在体内使用 i-NG进行生物力学能量收集的生物学可行性。