Porous Triboelectric Nanogenerator for Load Sensing of Total Knee Replacement

This study addresses the critical need for self-powered, durable pressure sensors in total knee replacement (TKR) implants to enable the collection of postoperative information. The scope of this research encompasses the design, development, and testing of a triboelectric nanogenerator (TENG) integrated into an instrumented knee implant for energy harvesting and pressure sensing. The authors’ unique approach involves utilizing a porous silicone rubber as a dielectric material. This allows the TENG to withstand forces up to 2000 N and generate a maximum power output of$18\,\mu \text{W}$. Theoretical modeling combined with experimental validation provides deeper insight into the fundamental operating principles. We elucidate the TENG output performance under an MTS servo-hydraulic load frame compared with a VIVO joint simulator. Other important characteristics, such as load sensitivity and the influence of porosity, are also presented. The proposed TENG shows great potential as a pressure sensor in TKR applications, offering high sensitivity, stability, and low cost.