Active colloids with collective mobility status and research opportunities

Abstract

The collective mobility of active matter (self-propelled objects that transduce energy into mechanical work to drive their motion, most commonly through fluids) constitutes a new frontier in science and achievable technology. This review surveys the current status of the research field, what kinds of new scientific problems can be tackled in the short term, and what long-term directions are envisioned. We focus on: (1) attempts to formulate design principles to tailor active particles; (2) attempts to design principles according to which active particles interact under circumstances where particle-particle interactions of traditional colloid science are augmented by a family of nonequilibrium effects discussed here; (3) attempts to design intended patterns of collective behavior and dynamic assembly; (4) speculative links to equilibrium thermodynamics. In each aspect, we assess achievements, limitations, and research opportunities.

Evolution of Self‐Propelled Objects: From the Viewpoint of Nonlinear Science

“…[1][2][3][4][95][96][97][98][99][100][101] Most of these studies focus on miniaturization likem icromotors and functionalization such as aJ anus particle. [1][2][3][4][95][96][97][98][99][100][101] Most of these studies focus on miniaturization likem icromotors and functionalization such as aJ anus particle.…”

“…Such as elf-propelled particleh as been well investigated, and discussed in several review papers [1][2][3] and books. As H 2 O 2 is decomposed on the surface of the particle, its inhomogeneous concentration around the particle can provide ad riving force originated from diffusiophoresis.…”

“…TheB Zs olution is typically am ixture of four components:b romate ion (BrO 3 À ), an acid (H 2 SO 4 or HNO 3 ), as ubstrate (malonic acid, citric acid, or 1,4-cyclohexanedione), and ac atalyst[ Ce 3 + ,F e(phen) 3 2 + ,o r Ru(bpy) 3 2 + ]. TheB Zs olution is typically am ixture of four components:b romate ion (BrO 3 À ), an acid (H 2 SO 4 or HNO 3 ), as ubstrate (malonic acid, citric acid, or 1,4-cyclohexanedione), and ac atalyst[ Ce 3 + ,F e(phen) 3 2 + ,o r Ru(bpy) 3 2 + ].…”

Nanoparticle‐Shelled Catalytic Bubble Micromotor

“…However, missing in this research area, are investigations of gas‐cored micromotors with a permanent buoyancy force. Moreover, the next important area of research in this field is the realization of active swimmers that can autonomously sense, interact, and assemble to achieve dynamic self‐assembly . For swarming, collective behaviors with contactless short‐ and long‐range interactions among active particles must be considered, which can be modulated by light, magnetic, and acoustic fields.…”

“…Moreover, the next important area of research in this field is the realization of active swimmers that can autonomously sense, interact, and assemble to achieve dynamic self-assembly. [19,20] For swarming, collective behaviors with contactless shortand long-range interactions among active particles must be considered, [21,22] which can be modulated by light, [23,24] magnetic, [25] and acoustic [26] fields.In this study, we report a new type of gas-cored micromotors, which are intrinsically buoyant in liquids. These micromotors have thin shells made of silica nanoparticles and are half-coated with a Ti/Pt catalyst.…”