Macroscopic, artificial active matter

Artificial active matters on a macroscopic scale, including vibrating particles, robots, and camphor boats, have attracted increasing attentions due to their uniform properties, rich and easily controllable parameters, convenient observation, and the independence of biochemical processes from physical processes, especially providing these unique advantages for researching the collective behaviors under strong confinement and crowded surroundings. In this review, we present an overview of motion models, mechanisms, and dynamic characteristics of various active particles, both in free and complex media. Additionally, we delve into the collective behaviors of "dry" active matter, covering structural and dynamic properties observed in experiments and theoretical models. We summarize the impact of hydrodynamic interactions on the dynamics and structures of these active particles within hydrodynamic environments. Lastly, we discuss emerging opportunities and challenges for future advancement of macroscopic artificial active matter.