Yunfeng Shi

Assistant Professor, Department of Materials Science and Engineering
School of Engineering · Rensselaer Polytechnic Institute
MRC RM114, 110 8th Street, Troy, NY 12180
Email: shiy2@rpi.edu 
Office: (518) 276-6729
Fax: (519) 276-855

CV: pdf or html

Using state-of-the-art computational methods, we aim to elucidate molecular-level mechanisms in advanced materials systems and design active nanostructures for energy related applications. Areas of interests include molecular motors, nanoporous materials, energetic materials, metallic glasses and metal-semiconductor interfaces.

7. Y. F. Shi, "Size-independent shear band formation in amorphous nanowires made from simulated casting", Applied Physics Letters, in press (2010).

6. Y. F. Shi, L. P. Huang, D. W. Brenner, "Computational Study of Nanometer-Scale Self-Propulsion Enabled by Asymmetric Chemical Catalysis", Journal of Chemical Physics, 131, 014705 (1-12) (2009).

5. Y. F. Shi, "A mimetic porous carbon model by quench molecular dynamics simulation", Journal of Chemical Physics, 128, 234707 (1-11) (2008).

4. Y. F. Shi, M. B. Katz, H. Li, M. L. Falk, "Evaluation of the 'disorder temperature' and free volume formalisms via simulations of shear banding in amorphous solids", Physical Review Letters, 98, 185505 (1-4) (2007).

3. Y. F. Shi, M. L. Falk, "Shear localization and percolation of stable structure in amorphous solids", Physical Review Letters, 95, 095502 (1-4) (2005).

2. Y. F. Shi, M. L. Falk, "Structural transformation and localization during simulated nanoindentation of a non-crystalline metal film", Applied Physics Letters, 86, 011914 (1-3) (2005).

1. J. Bording, B. Li, Y. F. Shi, J. M. Zuo, "Size- and shape-dependent energetics of nanocrystal interfaces: Experiment and simulation", Physical Review Letters, 90, 226104 (1-4) (2003).

Materials with pores in the nanometer scales possess many unusual properties and have applications in many areas such as energy storage/conversion, catalysis, and molecular separation. There are at two long-standing questions that need to be addressed: (1) generation of realistic nanoporous model; (2) simultaneous modeling of chemical reaction and mass transport. This project aims to solve the above issues.

A direct result of this project is an integrated nano-scale reaction cell model that is capable of simulating the dynamical processes of chemical reaction in a realistic catalytic porous structure. Such a model can be extended to simulate many economical and environmental-critical phenomena such as electricity generation in fuel cell, hydrogen generation/storage and water purification. For instance, a prototype fuel cell system can be constructed by integrating anode and cathode electrodes into a reaction cell model with proper reactants and catalysts.

Bio-molecular motors are fascinating nanoscale transducers that turn chemical energy into mechanical work. There are tremendous interests to understand how nature works in molecular motors and also how to design artificial ones with comparable size and efficiency. The basic research strategy in this area is nothing new to materials scientists. In fact, many experimental techniques and theoretical tools are common in both fields. Non-equilibrium dynamics, diffusion, chemical reaction and conformational change (phase transformation) are all essential ingredients of how bio-molecular motor works, which are also traditional topics in materials science.

Due to lack of experimental data, computational studies on molecular motors play an important role in providing thermodynamics data and kinetic pathway. This project will elucidate the energy conversion mechanism of a molecular motor which operates on similar principles as bio-molecular motors, and also provide predictive tools for designing and optimizing artificial molecular motors.

Animation of an autonomous nano-rocket (4MB, Green atoms are catalysts, blue atoms are reactants and yellow atoms represent products, more details in JCP Preprint)