John P. Collier

Myron Tribus Professor of Engineering Innovation, Emeritus

john.p.collier@dartmouth.edu

Research Interests

Design and analysis of orthopedic prostheses; design and metallurgy of porous-metal-coated implants; study of implant/host interfaces; growth and repair of cartilage

Education

AB, Engineering Sciences, Dartmouth College 1972
BE, Engineering, Thayer School of Engineering 1973
ME, Engineering, Thayer School of Engineering 1975
DE, Engineering, Thayer School of Engineering 1977

Awards

Professional Activities

Society for Biomaterials
Orthopaedic Research Society
American Academy of Orthopaedic Surgeons
Hip Society
Research consultant, Canadian Oxygen, Ltd., DuPont Inc., and DePuy, a Johnson and Johnson company

Research Projects

Joint replacement technology
Joint replacement technology
Joint replacement technology research is conducted within the Dartmouth Biomedical Engineering Center for Orthopaedics (DBEC). Founded at Thayer School in 1976, DBEC is the largest joint implant retrieval program of its type in the country and, with over 9000 specimens, has the biggest collection of retrieved joint implants in the world. Since the inception of this program—in affiliation with Dartmouth-Hitchcock—Thayer School researchers have systematically identified and solved most problems related to joint replacement production, design, and materials.

Remaining issues and current foci of the program include:
- determination of the rate of oxidation in vivo of polyethylene subjected to new sterilization techniques
- performance of new crosslinked polyethylene materials
- wear of new metal-on-metal and ceramic-on-ceramic technologies
Orthopaedic biomaterials and tribology

Orthopaedic biomaterials and tribology

Orthopaedic biomaterials and tribology research focuses on the measurement and prediction of friction, wear, and surface temperatures during sliding in mechanical components. Debris generation from polyethylene wear is considered the biggest problem facing joint replacement today. Current research on cross-linked polyethylene is targeting this problem which involves an analysis of the trade-offs between wear resistance achieved by cross links, and toughness and contact fatigue resistance of the polymer. Tribological studies of polymers analyze wear, contact fatigue and viscoelastic behavior in oscillatory sliding or rolling/sliding contact.