This book provides an expert introduction to active fluids systems, covering simple to complex environments.

The term active fluids refers to motions that are created by transforming energy from the surroundings into directed motion. There are many examples, both natural and synthetic, including individual swimming bacteria or motile cells, drops and bubbles that move owing to surface stresses (so-called Marangoni motions), and chemical- or optical-driven colloids. Investigations into active fluids provide new insights into non-equilibrium systems, have the potential for novel applications, and open new directions in physics, chemistry, biology and engineering. This book provides an expert introduction to active fluids systems, covering simple to complex environments. It explains the interplay of chemical processes and hydrodynamics, including the roles of mechanical and rheological properties across active fluids, with reference to experiments, theory, and simulations. These concepts are discussed for a variety of scenarios, such as the trajectories of microswimmers, cell crawling and fluid stirring, and apply to collective behaviours of dense suspensions and active gels. Emerging avenues of research are highlighted, ranging from the role of active processes for biological functions to programmable active materials, showcasing the exciting potential of this rapidly-evolving research field.

This volume contains a collection of review articles on the current topics of non-equilibrium soft matter physics written by leading experts in the field. It deals with topics such as evaporation, structual rheology, and active matter.

This book deals with those properties of non-equilibrium soft matter that deviate greatly from the bulk properties as a result of nanoscale confinement.The ultimate physical origin of these confinement effects is not yet fully understood. At the state of the art, the discussion on confinement effects focuses on equilibrium properties, finite size effects and interfacial interactions. However this is a limited vision which does not fully capture the peculiar behaviour of soft matter under confinement and some exotic phenomena that are displayed. This volume will be organized in the following three main themes. Equilibration and physical aging: treating non-equilibrium via the formal methodology of statistical physics in bulk, we analyse physical origin of the non-equilibrium character of thin polymer. We then focus on the impact of nanoconfinement on the equilibration of glasses of soft matter (a process of tremendous technological interest, commonly known as physical aging), comparing the latest trends of polymers in experiments, simulations with those of low-molecular weight glass formers. Irreversible adsorption: the formation of stable adsorbed layers occurs at timescales much larger than the time necessary to equilibrate soft matter in bulk. Recent experimental evidence show a strong correlation between the behaviour of polymers under confinement and the presence of a layer irreversibly adsorbed onto the substrate. This correlation hints at the possibility to tailor the properties of ultrathin films by controlling the adsorption kinetics. The book reports physical aspects of irreversible chain adsorption, such as the dynamics, structure, morphology, and crystallization of adsorbed layers. Glass transition and material properties: this section of the book focuses on the spread of absolute values in materials properties of confined systems, when measured by different experimental and computation techniques and a new method to quantify the effects of confinement in thin films and nanocomposites independently on the investigation procedure will be presented.

Soft matter is a concept which covers polymers, liquid crystals, colloids, amphiphilic molecules, glasses, granular and biological materials. One of the fundamental characteristic features of soft matter is that it exhibits various mesoscopic structures originating from a large number of internal degrees of freedom of each molecule. Due to such intermediate structures, soft matter can easily be brought into non-equilibrium states and cause non-linear responses by imposing external fields such as an electric field, a mechanical stress or a shear flow. Volume 4 of the series in Soft Condensed Matter focuses on the non-linear and non-equilibrium properties of soft matter. It contains a collection of review articles on the current topics of non-equilibrium soft matter physics written by leading experts in the field. The topics dealt with in this volume includes rheology of polymers and liquid crystals, dynamical properties of Langmuir monolayers at the air/water interface, hydrodynamics of membranes and twisted filaments as well as dynamics of deformable self-propelled particles and migration of biological cells. This book serves both as an introduction to students as well as a useful reference to researchers.