Alejandro Strachan
School of Materials Engineering and Birck Nanotechnology Center
Purdue University

Predictive modeling of materials and devices: from nanoelectronics to polymer composites for aerospace

Location: EB1 Room 1011

Friday, February 14th 2014 - 11:00 am

Predictive, physics-based modeling with quantified uncertainties has the potential to revolutionize design and certification of materials and devices. Accomplishing this requires not only advances in modeling and simulation but also their synergistic combination with experiments via rigorous methods to quantify uncertainties and arrive at the desired decision in an optimal manner. I will illustrate our recent progress in the field by way of several applications focusing on the following two representative efforts:

Atomistic simulations of nanoscale electrometallization cells for nanoelectronics. These resistance-switching devices operate via the electrochemical formation and disruption of metallic filaments and our simulations predict switching timescales ranging from hundreds of picoseconds to a few nanoseconds for device dimensions corresponding to the scaling limit. The simulations provide the first atomic-scale picture of the operation of these devices and show that stable switching proceeds via the formation of small metallic clusters and their progressive chemical reduction as they become connected to the cathode.

Molecular simulations of thermoset polymers and their composites. We use molecular simulations to characterize the curing of these class of polymers and characterize the thermo-mechanical response of the resulting structures. The predictions are in good agreement with available experimental data and show that atomistic simulations can capture non-trivial trends in polymer physics including the effect of temperature, thermal history and strain rate in yield and post-yield behavior. In addition, the simulations provide insight and properties that are difficult to obtain experimentally. In particular, we characterize how size effects the response of thin films including their glass transition temperature, stiffness and yield stress and develop an energy based yield criteria applicable for a wide range of loadings including different amounts of deviatoric and volumetric loads.

North Carolina State University