3D printed clamps to study the mechanical properties of tendons at low strains

Abstract

Various clamp designs have been proposed over the years with different degrees of complexity and actual performance vis-à-vis correct grip and reduced impact on the surface strains of the tendon sample. The previous studies all focused on impact on ultimate tensile strain and Young’s modulus of the tendons. Here an innovative clamp design is proposed that utilizes the fairly recently available technology that is 3D printing to produce a made-to-measure tendon sleeve that encloses the sample ends and also enables straightforward alignment within the testing equipment. All experiments are carried out using the superficial digital flexor tendons obtained from pig hind legs. The Young’s moduli for the linear region of the tendon obtained using this clamp design are very similar to those obtained using the cryo Jaw by other researchers for the same tendon. Furthermore, negative Poisson’s ratios are also obtained for the toe-region, in agreement with previous work.