The Orthopedic Tissue Engineering and Materials Lab at the University of North Carolina Charlotte (UNCC) was the winner of ADMET, Inc's 20 year anniversary celebration biomedical testing system giveaway. Drs. Ahmed El-Ghannam and Nigel Zheng at UNCC head a research team involved with the use of bioactive ceramic and bioactive ceramic-polymer composites as orthopedic fixation devices. To fulfill their testing needs, ADMET has awarded the team an eXpert 81T 20 Nm (177 in-lb) Vertical Torsion Testing System equipped with the PC based MTESTQuattro® Materials Testing System and an immersion bath.
ADMET eXpert 81T Vertical Torsion Testing System for testing bioabsorbable bone screws according to ASTM F2502.
Drs. El-Ghannam and Zheng will use the torsion machine for testing bioactive ceramic-polymer composite orthopedic fixation devices according to ASTM F2502 Annex A1 & A2. Test method F2502-A1is used to measure torsional yield strength, maximum torque and breaking angle; while F2502-A2 is used to measure insertion torque for the bioactive screws.
Example torque vs. angle plot of a screw twisted to failure. Included on the plot is the 2 deg offset yield line.
You can find more information on bone screw torque testing at ADMET's Biomedical webpage.