Development of A Micro-Scale Impact Tester for Characterizing Dynamic Properties of Biological Structural Materials

This thesis presents the design and construction of a micro-scale, air powered, impact testing device for use in Virginia Tech's Biological and Bio-inspired Materials Laboratory. A brief overview of current projectile impact testers is presented along with motivation for the fabrication of a new testing system capable of firing a projectile with a maximum diameter of 0.5 mm at velocities ranging from 20 to 50 m/s. Initial design calculations and analysis were performed to optimize barrel length, projectile size, and air pressure for desired velocity ranges. Computer aided design was then utilized to create a digital model of the entire system before production began on the device.
Within the scope of this project was the development of a large-scale projectile impact tester as a proof of concept of the system's design that would later be utilized by other researchers as well as the micro-scale tester which carried over the lessons learned and design improvements from the larger device. The culmination of the project was the testing of biological samples (sea urchin spine cross sections) to prove the viability of the device and highlight its research niche. Future use cases and design improvements of the small-scale impact tester were also investigated as part of this thesis work.