Pure Torsion Mechanical Testing Device

The Team

The Problem

Dr. Marnie Saunders, an accomplished biomedical engineering professor with a research emphasis in orthopaedic biomechanics and bone cell mechanobiology, wanted a pure torsion mechanical testing device to analyze small animal bone biomechanics. The problem was that there were no pure torsion devices on the market. Every "torsion" testing device she found was actually a twisting device. This implies that only one side of the sample being tested is rotating while the other side is stationary. Our primary objective for this project was to create a pure torsion device which converts one translational input force into two equal and opposite rotational forces (pure torsion). Another requirement was that the device must allow for variability in sample size. We utilized a combination of gears and a rack and pinion to perform the conversion. With a limited budget, we chose to create a working 3D printed prototype as proof of concept. This is the first true pure torsion mechanical testing device and it can be scaled up for use with larger specimens. Our paper was accepted to be released as an article by the Journal of Mechanics in Medicine and Biology.