In this article, we report a wearable millimeter-size energy generator that yields instantaneous power of 2.1 W level from kinetic energy of human running motions. The generator, with a hybridization of piezoelectric and electromagnetic transductions, integrates mainly two major novel techniques: impact induced frequency up conversion effect for the piezoelectric generation and abrupt magnetic flux density change for the electromagnetic generation. The generator proves to be able to effectively harness energy from human motions, producing a power density over one order of magnitude higher than that of state-of-the-art work. This result is further validated by the charging performance, i.e. high charging rate and voltage into mF-level capacitors. Moreover, this wearable generator demonstrates the capability to charge a Li-on battery in dozens of minutes. This work can be of much significance for the development of self-charging battery powered wearable electronic devices.

在本文中，我们报告了一种可穿戴毫米大小的能量发生器，该能量发生器从人类跑步运动的动能中产生2.1 W的瞬时功率。该发电机结合了压电和电磁换能器，主要集成了两种主要的新技术：用于压电发电的冲击感应频率上转换效应和用于电磁发电的突然磁通密度变化。事实证明，该发电机能够有效利用人体运动产生的能量，产生的功率密度比最新技术高出一个数量级。充电性能（即高充电速率和mF级电容器的电压）进一步验证了该结果。此外，这种可穿戴式发电机展示了可以在数十分钟内为锂电池充电的功能。这项工作对于开发自充电电池供电的可穿戴电子设备具有重要意义。