MRI: Acquisition of a Nanoindenter for Characterization of Biological and Advanced Engineering Materials

Bucknell University, Lewisburg PA

Investigators

Abstract

Technical Summary: Nanoindentation is an advanced mechanical testing technique that probes the surface of a sample to measure material properties at small length scales. Because of its ability to measure mechanical properties with submicron resolution, nanoindentation has seen growing use in the characterization of advanced engineering and biological materials with relevant structural features at the nano- and microscales. Testing methods are well-established for stiff, elastic materials such as metals and ceramics. However, significant research opportunities exist in the application of these methods to complex, composite materials with nanoscale features and in the development of new analysis techniques for testing biological or polymeric materials that are compliant and viscoelastic. This project involves acquisition of an instrumented nanoindentation system to augment existing materials characterization research in the departments of biomedical engineering, chemical engineering, mechanical engineering and biology at Bucknell University, a predominantly undergraduate liberal arts institution. Specific projects that would be enabled or enhanced by this instrument include: development of new nanoindentation methods for the characterization of compliant, viscoelastic materials such as soft tissues and hydrogels; studying the effects of nanofiller position and orientation on local mechanical property enhancement in polypropylene-graphite nanocomposites; studying the effects of particle size and processing parameters on the mechanical properties of the surface layer of cold spray tungsten carbide-cobalt nanocomposite coatings; and assessment of variation of the material properties of turtle shell bone to investigate the evolution of turtle shells and improve computational models of their structure. The requested nanoindentation system will foster multi-department and multi-institutional collaborative faculty research opportunities, provide hands-on nanomechanical testing experience for undergraduate and masters students through courses and research projects, and be utilized in outreach programs to increase the exposure of pre-college students to this advanced materials characterization technique. Layman Summary: Nanoindentation is an advanced materials testing technique that measures mechanical properties by pressing a very small tip into a sample of material at precise locations. Nanoindentation is typically used to test either very small samples (including thin films with thicknesses much less than a human hair) or small regions within larger, complex samples - materials that cannot be testing using traditional mechanical testing tools. Significant research opportunities exist for using nanoindentation to study composite materials with small-scale features of interest, and for improving nanoindentation methods for testing of soft polymers and biological materials. This proposal seeks support for an instrumented nanoindentation system to extend existing research programs in the departments of biomedical engineering, chemical engineering, mechanical engineering and biology at Bucknell University, a predominantly undergraduate liberal arts institution. Specific projects that would be enabled or enhanced by this instrument include: development of new nanoindentation methods for testing soft tissues and hydrogels; studying the effects of different manufacturing processes on properties of advanced polypropylene-graphite nanocomposites and tungsten carbide-cobalt nanocomposite coatings with industrial applications; and measuring the material properties of turtle shell bone to investigate the evolution of turtle shells and improve computational models of their structure. The requested nanoindentation system will support multi-department and multi-institutional collaborative faculty research opportunities, provide hands-on experience for undergraduate and masters students through courses and research projects, and be used in outreach programs to increase the exposure of pre-college students to this advanced materials characterization technique.