Differently from passive Brownian particles, active particles, also known as self-propelled
Brownian particles or microswimmers and nanoswimmers, are capable of taking up energy …

Locomotion and transport of microorganisms in fluids is an essential aspect of life. Search
for food, orientation toward light, spreading of off-spring, and the formation of colonies are …

Active fluids exhibit spontaneous flows with complex spatiotemporal structure, which have
been observed in bacterial suspensions, sperm cells, cytoskeletal suspensions, self …

Self-propelled particles include both self-phoretic synthetic colloids and various
microorganisms. By continually consuming energy, they bypass the laws of equilibrium …

Cell motility in viscous fluids is ubiquitous and affects many biological processes, including
reproduction, infection and the marine life ecosystem. Here we review the biophysical and …

Active particles contain internal degrees of freedom with the ability to take in and dissipate
energy and, in the process, execute systematic movement. Examples include all living …

Most swimming bacteria are capable of following gradients of nutrients, signaling molecules
and other environmental factors that affect bacterial physiology. This tactic behavior became …

Active crystals are highly ordered structures that emerge from the self-organization of motile
objects, and have been widely studied in synthetic, and bacterial, active matter. Whether …

A celebrated and controversial hypothesis suggests that some biological systems—parts,
aspects, or groups of them—may extract important functional benefits from operating at the …

We review theoretical models of individual motility as well as collective dynamics and
pattern formation of active particles. We focus on simple models of active dynamics with a …