Ibrahim Alwathiqbellah, Yamomo Geofrey, Willing Ryan, Towfighian Shahrzad
University of Texas at Tyler, 3900 University Blvd, Tyler, TX 75799, USA.
University of Western Ontario, London, ON N6A 3K7, Canada.
J Intell Mater Syst Struct. 2021 Jan;32(1):16-28. doi: 10.1177/1045389X20948581. Epub 2020 Aug 20.
Triboelectric energy harvesting is a relatively new technology showing promise for biomedical applications. This study investigates a triboelectric energy transducer for potential applications in total knee replacement (TKR) both as an energy harvester and a sensor. The sensor can be used to monitor loads at the knee joint. The proposed transducer generates an electrical signal that is directly related to the periodic mechanical load from walking. The proportionality between the generated electrical signal and the load transferred to the knee enables triboelectric transducers to be used as self-powered active load sensors. We analyzed the performance of a triboelectric transducer when subjected to simulated gait loading on a joint motion simulator. Two different designs were evaluated, one made of Titanium on Aluminum, (Ti-PDMS-Al), and the other made of Titanium on Titanium, (Ti-PDMS-Ti). The Ti-PDMS-Ti design generates more power than Ti-PDMS-Al and was used to optimize the structural parameters. Our analysis found these optimal parameters for the Ti-PDMS-Ti design: external resistance of 304 Ω, a gap of 550 , and a thickness of the triboelectric layer of 50 . Those parameters were optimized by varying resistance, gap, and the thickness while measuring the power outputs. Using the optimized parameters, the transducer was tested under different axial loads to check the viability of the harvester to act as a self-powered load sensor to estimate the knee loads. The forces transmitted across the knee joint during activities of daily living can be directly measured and used for self-powering, which can lead to improving the total knee implant functions.
摩擦电能量收集是一项相对较新的技术，在生物医学应用方面显示出前景。本研究调查了一种摩擦电能量转换器，用于全膝关节置换（TKR）中的潜在应用，既作为能量收集器又作为传感器。该传感器可用于监测膝关节处的负荷。所提出的转换器产生与行走时的周期性机械负荷直接相关的电信号。所产生的电信号与传递到膝盖的负荷之间的比例关系使摩擦电转换器能够用作自供电有源负荷传感器。我们在关节运动模拟器上对摩擦电转换器施加模拟步态负荷时分析了其性能。评估了两种不同的设计，一种是钛-聚二甲基硅氧烷-铝（Ti-PDMS-Al），另一种是钛-聚二甲基硅氧烷-钛（Ti-PDMS-Ti）。Ti-PDMS-Ti设计比Ti-PDMS-Al产生更多的功率，并用于优化结构参数。我们的分析发现了Ti-PDMS-Ti设计的这些最佳参数：外部电阻为304Ω，间隙为550，摩擦电层厚度为50。在测量功率输出时，通过改变电阻、间隙和厚度来优化这些参数。使用优化后的参数，在不同轴向负荷下对转换器进行测试，以检查该收集器作为自供电负荷传感器来估计膝盖负荷的可行性。在日常生活活动中通过膝关节传递的力可以直接测量并用于自供电，这可以改善全膝关节植入物的功能。
