We the Droplets: A Constitutional Approach to Active and Self-Propelled Emulsions

Abstract

The field of active matter, and particularly active emulsions, is growing rapidly, with significant progress made recently on both theoretical and experimental fronts. Here, we summarize experimental research progress related to active droplets. The constitution of active droplets, in particular the chemical compositions and structure of interfaces, is critical. We discuss how emulsion properties such as mechanism of motion, speed, trajectory, interaction strength, and lifetime are related to the droplet composition. We consider not only traditional single emulsions but also more complex variants, such as Janus droplets, Pickering emulsions, and multiple emulsions. Active behavior of isolated droplets as well as pairwise and multibody interactions between droplets is described. The influence of physical barriers that shape the local chemical gradients and fluid flow is also highlighted. This review provides perspective on the past, current, promising future experimental research directions in active droplet research.

References in corpus (17)

• The hydrodynamics of swimming microorganisms
• Spontaneous motion in hierarchically assembled active matter
• Self-propulsion of pure water droplets by spontaneous Marangoni stress driven motion
• 'Fuelled' motion: phoretic motility and collective behaviour of active colloids
• Self-propulsion of chemically-active droplets
• Chemotactic self-caging in active emulsions
• Nonlinear dynamics of a chemically-active drop: from steady to chaotic self-propulsion
• Directional self-locomotion of active droplets enabled by nematic environment
• Oscillatory rheotaxis of active droplets in microchannels
• Spontaneously rotating clusters of active droplets
• Rechargeable self-assembled droplet microswimmers driven by surface phase transitions
• Collective entrainment and confinement amplify transport by schooling micro-swimmers
• Solute Induced Jittery Motion of Self-Propelled Droplets
• Instability and self-propulsion of active droplets along a wall
• Rheotaxis of Active Droplets
• Swimming droplet in 1D geometries, an active Bretherton problem
• Dynamic control of speed and trajectories of active droplets in a nematic environment by electric field and focused laser beam

Cited by in corpus (7)

• A review of active matter reviews
• Light, Matter, Action: Shining light on active matter
• Deforming Active Droplets in Viscoelastic Media
• Interfacial activity dynamics of confined active droplets
• Mode-Switching of Active Droplets in Macromolecular Solutions
• Migration and deformation of a droplet enclosing an active particle
• Arrested on heating: controlling the motility of active droplets by temperature