Research Thrust 1: Composites for Orthopedic Bearings

Dr. Van Citters with students
Dr. Doug Van Citters with students. Image: Kathryn Lapierre

Team Lead:

Dr. Doug Van Citters 
Dartmouth College Thayer School

More than 1.5 million joint replacements are performed in the U.S. annually; however, 10% of those replacements fail, generally because the polymer used as bearing surfaces is based on a 50-year-old technology and has worn with use, fractured, or degraded. The fundamental need for wear-resistant, tough, and stable materials hasn’t been met. NH BioMade is developing models and fabrication methods for new biomaterials with improved functionality, longevity, and performance of orthopedic implants.

Hypothesis:

Highly localized shearing induced by Equal Channel Angular Extrusion promotes polymer chain interaction and entanglements, which in turn directly impacts particle fusion and structural development at the crystalline scale and achieves regional differences in porosity, conductivity, and modulus.

Intellectual Merit/Novelty:
  • Transformative approach to processing semicrystalline polymers with equal channel angular extrusion/processing (ECAE/ECAP)
  • ECAE avoids inherent polymer material tradeoffs between mechanical properties 
  • Modeling will allow optimization of bio-relevant properties including porosity and conductivity. 
  • Microstructural modifications may be made in the absence of chemical modification. 
  • Scalable processing combined with additive manufacturing will allow extension to spatially and functionally heterogeneous materials.

Favreau, H., Miroshnichenko, K., Solberg, P., Tsukrov, I. & Van Citters, D. (2022). “Shear enhancement of mechanical and microstructural properties of synthetic graphite and ultra-high molecular weight polyethylene carbon composites” Journal of Applied Polymer Science 52175. doi: 10.1002/app.52175

Jin, S., Korkolis, Y. P., & Li, Y. (2019). “Shear resistance of an auxetic chiral mechanical metamaterial”. International Journal of Solids and Structures, 174-175, 28–37. doi: 10.1016/j.ijsolstr.2019.06.005.  

Ma, C. & Li, Y. (2021) “Phase transition in polymer derived ceramics (PDCs) and its effect on mechanical response”. Proceedings at the 12th ICCM2021, 4th-8th July 2021 online,  Eds: G.R. Liu, Nguyen-Xuan Hung, ScienTech Publisher.

Ma, C., & Li, Y. (2021). “Modeling of Phase Transition in Fabrication of Polymer-Derived Ceramics (PDCS)”. International Journal of Computational Materials Science and Engineering. doi: 10.1142/s2047684121500329. 

Vasylevskyi, K. Miroshnichenko, K., Buklovskyi, S., Tsukrov, I., Grover, H., & Van Citters, D. (2020). “On Numerical Modeling of Equal Channel Angular Extrusion of Ultra High Molecular Weight Polyethylene”. ASME 2020 International Mechanical Engineering Congress and Exposition. Volume 3: Advanced Materials: Design, Processing, Characterization, and Applications doi: 10.1115/imece2020-24111.

Vasylevskyi, K., Tsukrov, I., Miroshnichenko, K., Buklovskyi, S., Grover, H. & Van Citters, D. (2021). “Finite Element Model of Equal Channel Angular Extrusion of Ultra High Molecular Weight Polyethylene”. Journal of Manufacturing Science and Engineering,  1-30. doi: 10.1115/1.4051189.

LEARN MORE ABOUT OUR RESEARCH THRUSTS:

Research Thrust 1
Orthopedic implants

Research Thrust 2
Sheet metal implants

Research Thrust 3

Tissue regeneration scaffolds

Research Thrust 4
Porous conductive biosensors