Artificial chemotaxis in micro/nanomotors.

Chemotaxis is the directional motion of objects in response to chemical gradients, a process that drives navigation in micro/nanomotors, enabling a bio-inspired transition toward autonomous direction control. However, current studies lack consistent mechanistic justification, definition, and standardized experimental validation. This review summarizes key physical principles governing active chemotaxis, surveys experimental strategies for generating chemical gradients and quantifying responses, and examines how individual chemotactic mechanisms and long-range, anisotropic chemical interactions give rise to emergent collective behaviors, while outlining prospective applications. Together, these efforts establish a principled engineering framework for advancing chemotaxis as a robust functional navigation modality in synthetic micro/nanomotors.