Abstract
Swarms and assemblies are ubiquitous in nature and they can perform complex collective behaviors and cooperative functions that they cannot accomplish individually. In response to light, some colloidal particles (CPs), including light active and passive CPs, can mimic their counterparts in nature and organize into complex structures that exhibit collective functions with remote controllability and high temporospatial precision. In this review, we firstly analyze the structural characteristics of swarms and assemblies of CPs and point out that light-controlled swarming and assembly of CPs are generally achieved by constructing light-responsive interactions between CPs. Then, we summarize in detail the recent advances in light-controlled swarming and assembly of CPs based on the interactions arisen from optical forces, photochemical reactions, photothermal effects, and photoisomerizations, as well as their potential applications. In the end, we also envision some challenges and future prospects of light-controlled swarming and assembly of CPs. With the increasing innovations in mechanisms and control strategies with easy operation, low cost, and arbitrary applicability, light-controlled swarming and assembly of CPs may be employed to manufacture programmable materials and reconfigurable robots for cooperative grasping, collective cargo transportation, and micro- and nanoengineering.
Highlights
Swarming and assembly represent a process in which multiple entities aggregate together and/or organize into ordered or functional structures through interactions with each other and their environment [1,2,3,4,5]
This review introduces the general principles of light-controlled swarming and assembly of colloidal particles (CPs) before amply summarizing the recent advances in the field in terms of employing optical forces, photochemical reactions, photothermal effects, and photoisomerizations
The light-controlled long-range interactions with an acting range from micrometers to millimeters are generally produced from direct optical forces or light–energy conversions, such as photochemical reactions, photothermal conversions, and photoisomerization, which induce diffusiophoresis, thermophoresis, convection, and Marangoni flows to regulate the collective behaviors of CPs [26,63,65,66,67]
Summary
Swarming and assembly represent a process in which multiple entities aggregate together and/or organize into ordered or functional structures through interactions with each other and their environment [1,2,3,4,5]. With the rapidly increasing innovations in mechanisms and strategies with easy operation, low cost, and arbitrary applicability, light-controlled swarming and assembly of CPs may offer new opportunities to develop programmable materials and reconfigurable robots for cooperative grasping, collective cargo transportation, and micro- and nanoengineering. CPs could generate autonomous motion or forced migration under a local or global chemical gradient and external fields (magnetic, electric, thermal, acoustic, flow, and optical fields) They may come together and form into swarms or assemblies through particle–particle and particle–interface interactions. The light-controlled long-range interactions with an acting range from micrometers to millimeters are generally produced from direct optical forces or light–energy conversions, such as photochemical reactions, photothermal conversions, and photoisomerization, which induce diffusiophoresis, thermophoresis, convection, and Marangoni flows to regulate the collective behaviors of CPs [26,63,65,66,67]. The photoresponses of CPs themselves or the environment (liquid media and substrates) are essential to generate the light-controlled short-range and long-range interactions to regulate the swarming and assembly of CPs
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
