Document Type
Article
Publication Date
2026
Keywords
Energy harvesting, Triboelectric nanogenerator, Instrumented knee implant, TPU foam, Carbon nanotubes, Self-charge excitation circuit, Biomedical sensor
Abstract
Aseptic loosening and joint instability remain the primary modes of failure in total knee arthroplasty (TKA). To provide real-time biomechanical load monitoring, this study presents a triboelectric nanogenerator (TENG) utilizing a carbon nanotube/foamed thermoplastic polyurethane (CNT/TPU) composite dielectric layer paired with a Kapton tape between dual electrodes. By leveraging the triboelectric effect, the device functions simultaneously as an energy harvester and a self-powered load sensor. To overcome power density limitations, a self-charge pumping mechanism via a multi-stage voltage multiplier circuit (VMC) was integrated and evaluated under physiological cyclic loading (2100 N at 1 Hz). The system’s charge dynamics were further validated using an analytical energy-based model. Across configurations, the 3-stage VMC dramatically boosted performance, achieving a peak apparent power output of 17 μW compared to 3 μW for the unamplified TENG, with optimal storage capacitance determined at 470 pF, 1 nF, and 10 nF for 1-, 2-, and 3-stage VMCs, respectively. While the 1-stage setup yielded the highest force sensitivity (94.45 mV/N), the 3-stage configuration maximized energy capture—highlighting a key operational trade-off between sensing sensitivity and power harvesting for implantable orthopedics.
Publisher Attribution
Published in Smart Materials and Structures. As the Version of Record of this article is going to be / has been published on a gold open access basis under a CC BY 4.0 licence, this Accepted Manuscript is available for reuse under a CC BY 4.0 licence immediately.
Recommended Citation
Abdalla, Osama; Hosseini, Maryam; Azami, Milad; Ameli, Amir; Salman, Emre; Stanacevic, Milutin; Willing, Ryan; and Towfighian, Shahrzad, "Carbon nanotube/ thermoplastic polyurethane (CNT/TPU)-Based Triboelectric Nanogenerator with Self-Charge Pumping for Implantable Knee Load Sensing and Energy Harvesting" (2026). Mechanical Engineering Faculty Scholarship. 56.
https://orb.binghamton.edu/mechanical_fac/56
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
