CBES Investigators

Sharon Glotzer

Isaac Bruss

Postdoctoral Fellow
Chemical Engineering

Chengyu Dai

PhD Pre-candidate
Physics

Mayank Agrawal

PhD Candidate
Chemical Engineering

Shannon Moran

PhD Candidate
Chemical Engineering

Wenbo Shen

PhD Candidate
Physics

Matthew Spellings

PhD Candidate
Chemical Engineering

Research Overview

Dissipative systems can exhibit rich and unexpected phenomena. In biological systems, energy dissipation maintains complex structures such as cells away from stationary equilibrium states. Such complex behavior is poorly understood and relatively underexploited in artificial materials, including those applicable for energy sciences. Using theory, modeling, and simulation, the Glotzer group is designing and researching colloidal and nanoparticle systems that sustain dissipative self-assembly far from equilibrium.

Using simulations, Glotzer and colleagues have discovered the ability to control the cellular shape of a particle assembly consisting of active boundary and passive interior particles. Each disc represents a gear-shaped particle subject to both external and internal driving forces. Yellow and blue particles are actively rotating clockwise and counter clockwise respectively, while grey particle are passive. The symmetry of the cell can be controlled by changing the number of alternately driven segments along the active boundary, while the magnitude of the buckling is controlled by the torque of the rotating particles.

 

We are investigating general concepts regulating self-assembly under such far-from-equilibrium conditions, that, by virtue of still possessing steady-states, are capable of performing complex functions. We are conducting simulations to provide a quantitative understanding of the link between the properties of the designed building blocks, and those of the non-equilibrium assemblies they form. Our objective is to provide design rules for a new class of next-generation materials, capable of such functions as, for example, performing mechanical work, controlling networks of chemical reactions, directing energy flows in multi-component arrays, and harnessing solar and thermal energy in the most optimized manner.

 

One of our focus studies is targeted at understanding ensembles of driven motors. Such active systems can be seen as the precursor to cellular and colloidal machines, nano-to-micro scale automata capable of performing complex tasks. We are interested in controllable deformations, switchable mechanical properties, and autonomous locomotion, all of which are a means to tune the emergent structures and behaviors of their collective assemblies. For example, we have found that the shape of individual particles have far-reaching effects on the global patterns that emerge. This theoretical work is inspired by nature but conceptually simplified. Various aspects of it are coupled closely to experiments by providing inspiration for novel material systems.