ERDC's Research at the Nanoscale
Most things that engineers care about are strongly influenced, if not controlled, by phenomena that occur at the atomic and molecular scale, that is, at the nanoscale. This includes material stiffness and strength, heat flow, fluid-structure interaction, chemical and light sensing, electrical resistance and capacitance, frictional effects, corrosion, and methods to harvest energy such as solar panels and other forms of light absorption as in solar heating.
ERDC's initial research at the nanoscale is directed toward nanoscale material studies, namely carbon nanotube-based materials. This study will later be augmented with other nanoscale studies into the other areas of interest to engineers. The initial study is a joint effort between the Information Technology Laboratory, the Construction Engineering Research Laboratory, and the Environmental Laboratory. The Research Team consists of civil engineers, physicists, computer scientists, chemists, electronic engineers, and material engineers.
Carbon nanotubes (CNTs) are the strongest molecules discovered with predicted tensile strengths of 15.5 million psi (107 GPa), or about 150 times that of high-strength steel, and a stiffness of about 5 times that of steel (150 million psi, or 1.1 TPa). Their density is 1/6 that of steel.
Making carbon nanotube macro materials that preserve these strength and stiffness characteristics requires developing optimized molecular designs, and then fabricating the material according to these designs. This program is laying the technical foundation to do just that, and is directed at both numerical simulations and at improving CNT synthesis methods. Its goal is to develop CNT tensile materials with a tensile strength of 1 million psi to Technology Readiness Level 4, which implies a demonstration at the laboratory level.
The Research Team has performed extensive molecular dynamics simulations that have revealed the effects of molecular defects on CNT tensile strength and critical strain, how to induce super toughness behavior in CNTs, and other significant discoveries of molecular phenomena that govern material behavior. Their research results were cited by the U.S. Army Engineer Research and Development Center as its "major basic research accomplishment" in July 2008 in its successful submission for the Army Laboratory of the Year contest.
-- December 2008
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