Master Student (alumnus)

NiTi Foams

Phone: 847.491.5933

Email: anselmneurohr2013(@u.northwestern.edu)

Address: 2220 Campus Drive, Evanston, IL 60208

B.Sc., Mechanical Engineering, University of Calgary

I received my B.Sc. degree in mechanical engineering from the University of Calgary. Concurrent to my studies in mechanical engineering I completed a specialization in biomedical engineering, which links two disciplines that have always fascinated me: engineering and medicine. My first introduction to engineering research was at the Calgary Center for Innovative Technology, where I worked during the summer after my sophomore year. One year later I found myself working here at Northwestern University. It was then that I was first introduced to materials science, which immediately appealed to me because of its fundamental approach to engineering problems.

The research of my Ph.D. focuses on the processing and characterization of nickel titanium (NiTi) with a tailorable internal architecture. NiTi belongs to a special class of alloys exhibiting the shape memory effect, allowing it to undergo very high deformations and yet return to its original shape after heating it above a particular temperature. How is this possible? The trick is that NiTi can deform reversibly via a mechanism that is unavailable to conventional materials, namely by a thermoelastic martensitic transformation. This refers to a phase transition between the low-symmetry martensite and high-symmetry austenite phases, which is diffusionless and simply involves the reorienting of the crystal lattice by the movement of twin boundaries in response to stress. Heating the material produces the austenite phase and restores the original lattice orientation, and thus the original bulk shape of the material. At certain compositions, this reverse transformation occurs immediately upon removal of the external load, obviating the need for heat to restore the material's original shape. This phenomenon is called superelasticity.

Publications

1. Neurohr AJ, Dunand DC. Shape-memory NiTi with two-dimensional networks of micro-channels. Acta Biomater. 2011;7:1862.