• Start: June 2020
• Status: Active - Currently analyzing results from the study and writing paper
• Lab Website: Experimental Biomechanics Laboratory
• Authors: E. G. Haas, E. D. Krech, E. A Friis
• Funding: K-INBRE P20 GM103418
• Awards: 1. K-INBRE Award of Excellence: "A Design Study of Piezoelectric Composite Materials with Compliant Layers to Analyze PZT Stress in Biomedical Devices” 19th Annual K-INBRE Symposium. January 15, 2021.

UNOFFICIAL Abstract

The use of electrical stimulation to improve bone growth in patient recovery is well documented and has successfully been used clinically. A proof-of-concept ovine study using a piezoelectric composite spinal fusion implant showed better and faster bone growth compared to a control. Piezoelectric composites capture human motion to power implants for improved bone growth as opposed to necessitating a battery or external power source. A discovery by our lab has revealed the addition of compliant layers between piezoelectric discs (i.e., Compliant Layer Adaptive Composite Stacks or CLACS) has shown an increase in power for a given PZT volume. The present study utilizes Finite Element Analysis (FEA) to evaluate variations in CLACS design with greater flexibility and less manufacturing resources than experimental studies allow. Initial models replicated experimental designs in order to test continuity between theoretical and experimental results. Changes to the initial specimen design include variations in top and bottom, side, and between disc compliant layer thicknesses. Analysis of overall disc average stress, as well as individual disc stresses, are analyzed. The results of this study could imply optimization and design of future implants leading to a reduction in implant cost, waste, and a broader use case for the application of this technology. Preliminary results suggest that stress between individual discs is often not consistent and varies with different configurations. Additionally, a diminishing return for increasing compliant layer thickness is observed. Further observations and results will be presented at the conference poster session.