Piezoelectric nanomaterial-polymer composites represent a unique paradigm for making flexible energy harvesting and sensing devices with enhanced devices’ performance. In this work, we studied various metal doped ZnO nanostructures, fabricated and characterized ZnO nanoparticle-PVDF composite thin film, and demonstrated both enhanced energy generation and motion sensing capabilities. Specifically, a series of flexible piezoelectric nanogenerators (PENGs) were designed based on these piezoelectric composite thin films. The voltage output from cobalt (Co), sodium (Na), silver (Ag), and lithium (Li) doped ZnO-PVDF composite as well as pure ZnO-PVDF samples were individually studied and compared. Under the same experimental conditions, the Li-ZnO based device produces the largest peak-to-peak voltage (3.43 Vpp) which is about 9 times of that of the pure ZnO based device, where Co-ZnO, Na-ZnO and Ag-ZnO are 1.2, 4.9 and 5.4 times, respectively. In addition, the effect of doping ratio of Li-ZnO is studied, and we found that 5 % is the best doping ratio in terms of output voltage. Finally, we demonstrated that the energy harvested by the device from finger tapping at ∼2 Hz can charge a capacitor with a large output power density of 0.45 W/cm³ and light up an ultraviolet (UV) light-emitting diode (LED). We also showed the device as a flexible wearable motion sensor, where different hand gestures were detected by the device with distinctive output voltage amplitudes and patterns.

压电纳米材料-聚合物复合材料代表了制造具有增强设备性能的灵活能量收集和传感设备的独特范例。在这项工作中，我们研究了各种金属掺杂的 ZnO 纳米结构，制造并表征了 ZnO 纳米颗粒-PVDF 复合薄膜，并展示了增强的能量生成和运动传感能力。具体来说，基于这些压电复合薄膜设计了一系列柔性压电纳米发电机（PENG）。分别研究和比较了钴 (Co)、钠 (Na)、银 (Ag) 和锂 (Li) 掺杂 ZnO-PVDF 复合材料以及纯 ZnO-PVDF 样品的电压输出。在相同的实验条件下，Li-ZnO基器件产生最大的峰峰值电压（3.43 Vpp），约为纯ZnO基器件的9倍，其中Co-ZnO、Na-ZnO和Ag- ZnO分别是1.2、4.9和5.4倍。此外，我们还研究了Li-ZnO掺杂比例的影响，发现就输出电压而言，5%的掺杂比例是最佳的。最后，我们证明了该设备通过~2 Hz 的手指敲击收集的能量可以为具有 0.45 W/cm ³大输出功率密度的电容器充电，并点亮紫外线 (UV) 发光二极管 (LED)。我们还展示了该设备作为一种灵活的可穿戴运动传感器，该设备可以检测到不同的手势，并具有独特的输出电压幅度和模式。