Design and Analysis of a Compliant 3D Printed Energy Harvester Package for Knee Implants

Instrumented implants provide the potential to measure the in vivo tibiofemoral forces that are transmitted through total knee replacements (TKR). The continuous feedback from instrumented implants can be used to objectively justify actions to reduce the risk of implant failure. The main obstacle in developing “smart implants” is reliably powering such devices. Energy harvesting mechanisms, such as the triboelectric effect, can be leveraged to produce usable electricity and measure the transmitted loads in TKRs. A compliant package that interlocks with commercially available TKR components was designed to house triboelectric generators (TEG). Prototypes were more compliant than what was expected from the computational models. During fatigue testing, the prototype failed prematurely due to inherent issues with additive manufacturing. However, these issues can be mitigated with improved post-processing techniques. This package serves as a novel approach to integrating self-powering load sensors in currently available knee implants