106 citations · 364 across the 11 of their papers we have counts for
11 papers
Theory of Capillary Tension and Interfacial Dynamics of Motility-Induced Phases
Luke Langford, Ahmad K. Omar
The statistical mechanics of equilibrium interfaces has been well-established for over a half century. In the last decade, a wealth of observations have made increasingly clear tha…
Remembering the work of Phillip L. Geissler: A coda to his scientific trajectory
Gregory R. Bowman, Stephen J. Cox, Christoph Dellago +19
Phillip L. Geissler made important contributions to the statistical mechanics of biological polymers, heterogeneous materials, and chemical dynamics in aqueous environments. He dev…
Phase Coexistence Implications of Violating Newton's Third Law
Yu-Jen Chiu, Ahmad K. Omar
Newton's third law, actio = reactio, is a foundational statement of classical mechanics. However, in natural and living systems, this law appears to be routinely violated for const…
Mechanical Theory of Nonequilibrium Coexistence and Motility-Induced Phase Separation
Ahmad K. Omar, Hyeongjoo Row, Stewart A. Mallory +1
Nonequilibrium phase transitions are routinely observed in both natural and synthetic systems. The ubiquity of these transitions highlights the conspicuous absence of a general the…
Topological Forces in a Model System for Reptation Dynamics
Ahmad K. Omar, Yuyuan Lu, Lijia An +1
We construct a micromechanical version of an early model for topologically constrained polymers -- a 2D chain amongst point-like uncrossable obstacles -- which allows us to explici…
Ballistic Ejection of Microdroplets from Overpacked Interfacial Assemblies
Xuefei Wu, Gautam Bordia, Robert Streubel +11
Spontaneous emulsification, resulting from the assembly and accumulation of surfactants at liquid-liquid interfaces, is an interfacial instability where microdroplets are generated…
Tuning Nonequilibrium Phase Transitions with Inertia
Ahmad K. Omar, Katherine Klymko, Trevor GrandPre +2
In striking contrast to equilibrium systems, inertia can profoundly alter the structure of active systems. Here, we demonstrate that driven systems can exhibit effective equilibriu…
Phase Diagram of Active Brownian Spheres: Crystallization and the Metastability of Motility-Induced Phase Separation
Ahmad K. Omar, Katherine Klymko, Trevor GrandPre +1
Motility-induced phase separation (MIPS), the phenomenon in which purely repulsive active particles undergo a liquid-gas phase separation, is among the simplest and most widely stu…
Dynamic Overlap Concentration Scale of Active Colloids
Stewart A. Mallory, Ahmad K. Omar, John F. Brady
By introducing the notion of a dynamic overlap concentration scale, we identify universal and previously unreported features of the mechanical properties of active colloids. These…
Microscopic Origins of the Swim Pressure and the Anomalous Surface Tension of Active Matter
Ahmad K. Omar, Zhen-Gang Wang, John F. Brady
The unique pressure exerted by active particles -- the "swim" pressure -- has proven to be a useful quantity in explaining many of the seemingly confounding behaviors of active par…
Swimming to Stability: Structural and Dynamical Control via Active Doping
Ahmad K. Omar, Yanze Wu, Zhen-Gang Wang +1
External fields can decidedly alter the free energy landscape of soft materials and can be exploited as a powerful tool for the assembly of targeted nanostructures and colloidal ma…