Chahari Mahmood, Salman Emre, Stanacevic Milutin, Willing Ryan, Towfighian Shahrzad
Binghamton University, 4400 Vestal Parkway East, Binghamton, NY 13902, USA.
Stony Brook University, Stony Brook, NY, USA.
Nano Energy. 2025 Aug;141. doi: 10.1016/j.nanoen.2025.111117. Epub 2025 May 11.
This study investigates the energy harvesting and sensing capabilities of piezoelectric nanogenerators (PENG) and triboelectric nanogenerators (TENG) for long-term load monitoring in total knee replacement (TKR). Multi-layered polyvinylidene fluoride (PVDF) films and cuboid-patterned silicone rubber embedded with dopamine-coated BaTiO particles (SR/BT@PDA) TENG are compared as energy harvesting-based load sensors. Unlike prior studies relying on simplified harmonic loading, this work utilizes physiologically relevant gait cycles covering realistic force ranges to precisely evaluate electrical output, sensitivity, and activity recognition capabilities. Results indicate forward-polarized TENG samples and upward-polarized PVDF layers generate significantly higher outputs, indicating the importance of dipole alignment for enhanced sensor efficiency. The harvesters' outputs show that the SR/BT@PDA TENG achieves a maximum apparent power output of 6 W at 1.5GΩ, while the PVDF reaches 2.7 W at 200MΩ under normal walking conditions. The SR/BT@PDA TENG outperforms PVDF in energy harvesting, reaching 140 V in 26 gait cycles for a 10nF capacitor and powering 60 LEDs, while PVDF charges the same capacitor to 33 V in nearly 19 gait cycles, powering 14 LEDs. The TENG's micro-cuboid surface patterning and synergistic effects of embedded piezoelectric material (BaTiO) enhance its output power density, whereas the multi-layered PVDF demonstrates reliable performance under diverse load conditions. Both sensors effectively detect diverse activities, including walking, jogging, and stair climbing. Overall, PVDF provides precise load monitoring by tracking dynamic force profiles, while TENG outperforms in energy harvesting. This study evaluates the potential of integrating TENG and PENG into TKR as energy-harvesting solutions for joint load monitoring without relying on external power sources.
本研究调查了用于全膝关节置换术（TKR）长期负荷监测的压电纳米发电机（PENG）和摩擦电纳米发电机（TENG）的能量收集和传感能力。将多层聚偏二氟乙烯（PVDF）薄膜和嵌入多巴胺包覆的钛酸钡颗粒（SR/BT@PDA）的长方体图案硅橡胶TENG作为基于能量收集的负荷传感器进行比较。与以往依赖简化谐波加载的研究不同，本研究利用涵盖实际力范围的生理相关步态周期来精确评估电输出、灵敏度和活动识别能力。结果表明，正向极化的TENG样品和向上极化的PVDF层产生的输出显著更高，表明偶极排列对提高传感器效率的重要性。收集器的输出表明，在正常行走条件下，SR/BT@PDA TENG在1.5GΩ时实现了6W的最大视在功率输出，而PVDF在200MΩ时达到2.7W。SR/BT@PDA TENG在能量收集方面优于PVDF，对于一个10nF的电容器，在26个步态周期内达到140V，并为60个发光二极管供电，而PVDF在近19个步态周期内将相同的电容器充电至33V，为14个发光二极管供电。TENG的微长方体表面图案和嵌入的压电材料（钛酸钡）的协同效应提高了其输出功率密度，而多层PVDF在不同负载条件下表现出可靠的性能。两种传感器都能有效检测包括行走、慢跑和爬楼梯在内的各种活动。总体而言，PVDF通过跟踪动态力分布提供精确的负荷监测，而TENG在能量收集方面表现更优。本研究评估了将TENG和PENG集成到TKR中作为无需外部电源的关节负荷监测能量收集解决方案的潜力。
