Related Experiment Video
Updated: Sep 29, 2025
10:56
Confocal Imaging of Confined Quiescent and Flowing Colloid-polymer Mixtures
Published on: May 20, 2014
12.3K
Confinement and Collective Escape of Active Particles
Igor S Aranson1, Arkady Pikovsky2,3
1Departments of Biomedical Engineering, Chemistry, and Mathematics, Penn State University, University Park, Pennsylvania 16802, USA.
Physical Review Letters
|March 25, 2022
Summary
Self-propelled particles in active matter can form crystalline structures when trapped. Adding more particles causes these trapped condensates to escape collectively, revealing insights into confinement effects.
Area of Science:
- Physics
- Complex Systems
- Statistical Mechanics
Background:
- Active matter studies self-propelled particle dynamics.
- Collective behavior in homogeneous systems is understood, but effects of inhomogeneities like traps are unclear.
Purpose of the Study:
- Investigate particle trapping and release mechanisms in inhomogeneous active matter.
- Understand how confinement and disorder influence self-propelled particle behavior.
Main Methods:
- Simulations of interacting, self-propelled particles.
- Analysis of particle aggregation and escape dynamics from traps.
Main Results:
- Particles form orbiting condensates with crystalline structures when trapped.
- Trapped condensates escape as a single unit when particle density increases.
Conclusions:
- Confinement and quenched disorder significantly impact active matter systems.
- Observed phenomena provide new insights into collective behavior in inhomogeneous environments.
Related Concept Videos
01:19Escape Velocities of Gases
1.1K
To escape the Earth's gravity, an object near the top of the atmosphere at an altitude of 100 km must travel away from Earth at 11.1 km/s. This speed is called the escape velocity. The temperature at which gas molecules attain the rms speed, which is equal to the escape velocity, can be estimated by using the equation for the average kinetic energy of the gas molecules. According to the kinetic theory of gas, the average kinetic energy of the gas molecules is proportional to its...
1.1K
01:23Equilibrium Conditions for a Particle
1.6K
When an object is in equilibrium, it is either at rest or moving with a constant velocity. There are two types of equilibrium: static and dynamic. Static equilibrium occurs when an object is at rest, while dynamic equilibrium occurs when an object is moving with a constant velocity. In both cases, there must be a balance of forces acting on the object.
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
1.6K
01:18First Law: Particles in Two-dimensional Equilibrium
5.3K
Recall that a particle in equilibrium is one for which the external forces are balanced. Static equilibrium involves objects at rest, and dynamic equilibrium involves objects in motion without acceleration; but it is important to remember that these conditions are relative. For instance, an object may be at rest when viewed from one frame of reference, but that same object would appear to be in motion when viewed by someone moving at a constant velocity.
Newton's first law tells us about...
Newton's first law tells us about...
5.3K
01:10First Law: Particles in One-dimensional Equilibrium
7.1K
Newton's first law of motion states that a body at rest remains at rest, or if in motion, remains in motion at constant velocity, unless acted on by a net external force. It also states that there must be a cause for any change in velocity (a change in either magnitude or direction) to occur. This cause is a net external force. For example, consider what happens to an object sliding along a rough horizontal surface. The object quickly grinds to a halt, due to the net force of friction. If...
7.1K
02:43Basic Postulates of Kinetic Molecular Theory: Particle Size, Energy, and Collision
35.0K
The ideal-gas equation, which is empirical, describes the behavior of gases by establishing relationships between their macroscopic properties. For example, Charles’ law states that volume and temperature are directly related. Gases, therefore, expand when heated at constant pressure. Although gas laws explain how the macroscopic properties change relative to one another, it does not explain the rationale behind it.
35.0K
03:48Behavior of Gas Molecules: Molecular Diffusion, Mean Free Path, and Effusion
29.7K
Although gaseous molecules travel at tremendous speeds (hundreds of meters per second), they collide with other gaseous molecules and travel in many different directions before reaching the desired target. At room temperature, a gaseous molecule will experience billions of collisions per second. The mean free path is the average distance a molecule travels between collisions. The mean free path increases with decreasing pressure; in general, the mean free path for a gaseous molecule will be...
29.7K