You probably already know that an engineer is someone who applies their technical knowledge for the betterment of humanity. A materials engineer is someone who uses their understanding of the science of materials to engineer a material's performance. For example, Jennifer Fino (B.S., MatE, 2004) uses her knowledge of materials to ensure that nickel titanium arterial stents perform as planned after implantation in the human body.
This tetrahedron symbolizes the links between the performance of a material and the science behind it (i.e., its properties, its 
structure and the synthesis or processing of the material). In simple terms, a materials engineer alters the three items at the base of the tetrahedron to get the desired performance out of the material. That desired performance may be "low environmental impact over the product life cycle." For example, we are experimenting with different material combinations for to extend the time before failure of the fuel cell pictured here.
