Nonreciprocal interactions induce persistent active clusters in binary colloids
Shoma Hara, Masazumi Okada, Keisuke Kittaka, Sho Tanami, Yuichi Iwasaki, Hiroaki Ishikawa, Kiwamu Yoshii, Yutaka Sumino
公開日: 2025/9/27
Abstract
We study binary colloids under AC electric fields, where electrohydrodynamic (EHD) flows generate nonreciprocal interactions. Mixing particles of different sizes produces self-propelled pairs that fragment and reassemble into persistent active clusters, unlike the static crystallization of single-sized systems. Agent-based and continuum models reproduce these dynamics and identify two key mechanisms: asymmetric pair propulsion and spray-like fission from excluded-volume polarity. These results establish a minimal, controllable platform for exploring nonreciprocal active matter and highlight nonreciprocity as a general route to engineer reconfigurable colloidal assemblies.