Skip to Main Content
Skip Nav Destination

This book provides an overview of the field of active matter and aims at bringing together major breakthroughs and future perspectives of physicists, biologists, material scientists, and engineers in this rapidly evolving area of research. It is intended to serve as a textbook for graduate students and beginning researchers, as it both includes descriptions of theoretical, computational, and experimental tools for the study of active matter systems and highlights exciting physical phenomena arising in biological as well as synthetic systems.

Active matter is composed of objects that convert energy from their surroundings into directed motion. Examples can be found at various length scales and involve biofilament-motor protein suspensions, swimming microorganisms, self-propelled colloids, drops and bubbles, crawling eukaryotic cells, and flying birds, to name a few. Major advances in experimental methods, ranging from the development of novel microscopy tools to the design of tailored microfluidic devices, together with continuously evolving data analysis methods, such as state-of-the-art algorithms for image analysis, make the study of active materials at different scales possible. In particular, they provide access to small length and time scales, where interactions between motor proteins and biofilaments lead to intriguing novel physics, and micro- to millimeter scales, where transport behaviors of microorganisms entail fascinating phenomena at the single cell and collective-cell level or the development of tissues can be resolved. We provide a general overview of the different systems involved in active matter research in Chapter 1 (What is ‘Active Matter’?) of this book.

It is important to highlight that active matter systems are inherently out of equilibrium, which calls for novel theoretical tools to capture the underlying physics as traditional theories from equilibrium statistical mechanics break down. This book addresses the fluid mechanics and statistical physics of active matter by considering the behavior of active agents at the single as well as collective level. While Chapter 2 (Hydrodynamics of Cell Swimming) introduces the modeling framework for individual swimming microorganisms, Chapter 3 (Active Nematics: Mesoscale Turbulence and Self-propelled Topological Defects) and Chapter 4 (An Introduction to Motility-induced Phase Separation) discuss the collective concepts of active nematics and motility-induced phase separation, respectively. Chapter 7 (Motility and Self-propulsion of Active Droplets) presents an overview of active droplets by including aspects of active nematics. Overall, these chapters aim at both introducing modeling frameworks and making the connections to experimental realizations. These approaches are complemented by computational studies of active matter, which are discussed in Chapter 10 (Computational Physics of Active Matter).

In contrast to perfect lab conditions, the behavior of active agents is generally affected by different environmental conditions, depending on the surroundings in which they operate. For example, microorganisms are ubiquitous in the ocean, the human body, and soil, where they are confronted with strong hydrodynamic flows, complex fluids, chemical fields, and geometric disorder. These topics are addressed in Chapter 5 (Active Transport in Complex Environments) and Chapter 9 (Rheology of Active Fluids).

An important aspect in active matter research concerns the interplay of active processes for the achievement of biological function or the design of functional materials. To provide a biological example, Chapter 6 (The Mitotic Spindle as Active Machinery) offers insights into the physics of the mitotic spindle, which is an active machinery responsible for capturing and segregating chromosomes during cell division. The functioning of the latter relies on the complex interplay of microtubules and motor proteins. As a synthetic counterpart, Chapter 8 (Autonomous Photothermally-driven Fluid Pumping and Particle Transport and Assembly) addresses transport driven by photothermally-driven fluid micropumps and assembly of synthetic particles.

Finally, we would like to thank our colleagues for contributing their chapters to our book and the staff from the Royal Society of Chemistry, who continuously assisted us during the process of designing and producing this book. We hope that the book will provide a useful guide for future generations of researchers in the study of active matter. We are excited to see where the journey of active matter research will take us next.

Christina Kurzthaler

Luigi Gentile

Howard A. Stone

Close Modal

or Create an Account

Close Modal
Close Modal