TitleTemperature switchable self-propulsion activity of liquid crystalline microdroplets.
Publication TypeJournal Article
Year of Publication2025
AuthorsKumar M, Sane S, Murali A, Thutupalli S
JournalSoft Matter
Date Published2025 Apr 17
ISSN1744-6848
Abstract

We report on a switchable emulsion droplet microswimmer by utilizing a temperature-dependent transition of the droplet phase. The droplets, made from a liquid crystalline (LC) smectic phase material ( = 25 °C), self-propel only in their nematic and isotropic phases at elevated temperatures ( ≥ 33.5 °C). This transition between motile and non-motile states is fully reversible - in the motile state, the droplets exhibit persistent motion and directional memory over multiple heating-cooling cycles. Furthermore, we distinguish the state of rest from the state of motion by characterizing the chemical and hydrodynamic fields of the droplets. Next, we map the motility behaviour of the droplets across varying surfactant concentrations and temperatures, observing that swimming occurs only at sufficiently high surfactant concentrations and temperatures above the smectic-nematic phase transition temperature ≥ 33.5 °C. Our work envisions the potential of LC emulsion droplets as temperature tunable microswimmers.

URLhttps://pubs.rsc.org/en/content/articlelanding/2025/sm/d4sm01382d
DOI10.1039/d4sm01382d
Alternate JournalSoft Matter
PubMed ID40242986