Work

Self-propulsion of liquid droplet assemblies controlled by the functionalities of their components

Year: 2025

Type: article

Abstract: The self-propulsion of droplet assemblies consisting of droplets of 1-decanol and either an ethyl salicylate (ES) or a composite droplet of ES and liquid polydimethylsiloxane (PDMS) is reported. The ES-PDMS composite droplets have an ES core covered by a PDMS layer that stabilizes the assembly significantly. Their self-propulsion exhibits characteristic predator-prey behavior, with a decanol droplet closely chasing the ES or ES-PDMS composite droplet, forming a bound droplet pair. Furthermore, the stability that PDMS gives the system enables us to construct more complex assemblies, such as two, three, and four decanol droplets closely chasing an ES-PDMS droplet, whose motion patterns depend strongly on the symmetry in the structure of the assemblies. Our findings demonstrate that long-lived assemblies composed of droplets with distinct functionalities can serve as a versatile platform for developing self-organizing and adaptive droplet systems, functioning as "droplet robots".

Source: Physical Chemistry Chemical Physics

DOI: 10.1039/d5cp00597c

Authors: Rony Mallick, Chiho Watanabe, Shinpei Tanaka

Institution: Hiroshima University

Language: English

Topic: Micro and Nano Robotics

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funder: Japan Society for the Promotion of Science

Awards: Mathematical modeling and analysis of the collective motion of self-propelled objects, Droplet robots designed by using self-propelled liquid droplets