Menthyl acetate powered self-propelled Janus sponge Marangoni motors with self-maintaining surface tension gradients and active mixing.

Autor: Archer RJ; Molecular Robotics Laboratory, Department of Robotics, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan. Electronic address: archer.richard.james.c8@tohoku.ac.jp., Ebbens SJ; Department of Chemical and Biological Engineering, University of Sheffield, Mappin Street, Sheffield S1 3JD, UK., Kubodera Y; Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan., Matsuo M; Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan; Graduate School of Arts and Sciences, The University of Tokyo, Meguro City, Tokyo 153-0041, Japan. Electronic address: muneyuki@hiroshima-u.ac.jp., Nomura SM; Molecular Robotics Laboratory, Department of Robotics, Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan. Electronic address: shinichiro.nomura.b5@tohoku.ac.jp.
Jazyk: angličtina
Zdroj: Journal of colloid and interface science [J Colloid Interface Sci] 2025 Jan 15; Vol. 678 (Pt B), pp. 11-19. Date of Electronic Publication: 2024 Aug 28.
DOI: 10.1016/j.jcis.2024.08.213
Abstrakt: Hypothesis: Small scale Marangoni motors, which self-generate motion by inducing surface tension gradients on water interfaces through release of surface-active "fuels", have recently been proposed as self-powered mixing devices for low volume fluids. Such devices however, often show self-limiting lifespans due to the rapid saturation of surface-active agents. A potential solution to this is the use volatile surface-active agents which do not persist in their environment. Here we investigate menthyl acetate (MA) as a safe, inexpensive and non-persistent fuel for Marangoni motors.
Experiments: MA was loaded asymmetrically into millimeter scale silicone sponges. Menthyl acetate reacts slowly with water to produce the volatile surface-active menthol, which induces surface tension gradients across the sponge to drive motion by the Marangoni effect. Videos were taken and trajectories determined by custom software. Mixing was assessed by the ability of Marangoni motors to homogenize milliliter scale aqueous solutions containing colloidal sediments.
Findings: Marangoni motors, loaded with asymmetric "Janus" distributions of menthyl acetate show velocities and rotational speeds up to 30 mm s -1 and 500 RPM respectively, with their functional lifetimes scaling linearly with fuel volume. We show these devices are capable of enhanced mixing of solutions at orders of magnitude greater rates than diffusion alone.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE
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