Self-propulsion of a metallic superoleophobic micro-boat.

The self-propulsion of a heavy, superoleophobic, metallic micro-boat carrying a droplet of various aqueous alcohol solutions as a fuel tank is reported. The micro-boat is driven by the solutocapillary Marangoni flow. The jump in the surface tension owing to the condensation of alcohols on the water surface was established experimentally. Maximal velocities of the self-propulsion were registered as high as 0.05m/s. The maximal velocity of the center mass of the boat correlates with the maximal change in the surface tension, due to the condensation of alcohols. The mechanism of the self-locomotion is discussed. The phenomenological dynamic model describing the self-propulsion is reported.

[1]  Directed Autonomic Flow: Functional Motility Fluidics , 2015, Advanced materials.

[2]  Edward Bormashenko,et al.  Progress in understanding wetting transitions on rough surfaces. , 2015, Advances in colloid and interface science.

[3]  Christophe Clanet,et al.  Leidenfrost on a ratchet , 2011 .

[4]  T. Darmanin,et al.  Chemical and physical pathways for the preparation of superoleophobic surfaces and related wetting theories. , 2014, Chemical reviews.

[5]  Rebecca L. Agapov,et al.  Length scale of Leidenfrost ratchet switches droplet directionality. , 2014, Nanoscale.

[6]  E. Lauga,et al.  Autophoretic locomotion from geometric asymmetry , 2015, The European physical journal. E, Soft matter.

[7]  P. Gennes,et al.  Capillarity and Wetting Phenomena , 2004 .

[8]  Satoshi Nakata,et al.  Characteristic self-motion of a camphor boat sensitive to ester vapor. , 2005, Langmuir : the ACS journal of surfaces and colloids.

[9]  Joseph Wang,et al.  Can man-made nanomachines compete with nature biomotors? , 2009, ACS nano.

[10]  Youmin Hou,et al.  Directional transport of high-temperature Janus droplets mediated by structural topography , 2016, Nature Physics.

[11]  M. Chaudhury,et al.  Ratcheting motion of liquid drops on gradient surfaces. , 2004, Langmuir : the ACS journal of surfaces and colloids.

[12]  A. Snezhko,et al.  Pulsating–gliding transition in the dynamics of levitating liquid nitrogen droplets , 2008 .

[14]  Satoshi Nakata,et al.  Synchronized Self-Motion of Two Camphor Boats , 2001 .

[15]  D. Vella.  Floating Versus Sinking , 2015 .

[16]  N. Nguyen,et al.  Evaporation of Ethanol-Water Binary Mixture Sessile Liquid Marbles. , 2016, Langmuir : the ACS journal of surfaces and colloids.

[17]  Alexander A. Nepomnyashchy,et al.  Interfacial Phenomena and Convection , 2001 .

[18]  Rebecca L. Agapov,et al.  Asymmetric wettability of nanostructures directs leidenfrost droplets. , 2014, ACS nano.

[19]  Metal-Ion-Dependent Motion of Self-Propelled Droplets Due to the Marangoni Effect. , 2015, The journal of physical chemistry. B.

[20]  E. Bormashenko,et al.  Self-Propulsion of Liquid Marbles: Leidenfrost-like Levitation Driven by Marangoni Flow , 2015, 1502.04292.

[21]  Olli Ikkala,et al.  Vapour-driven Marangoni propulsion: continuous, prolonged and tunable motion , 2012 .

[22]  G. Whitesides,et al.  Autonomous Movement and Self‐Assembly , 2002 .

[23]  Hongping Zhao,et al.  Elasticity-driven droplet movement on a microbeam with gradient stiffness: a biomimetic self-propelling mechanism. , 2008, Journal of colloid and interface science.

[24]  Orlin D. Velev,et al.  Active particles propelled into researchers’ focus , 2016 .

[25]  O. Velev,et al.  Gel-based self-propelling particles get programmed to dance. , 2012, Langmuir : the ACS journal of surfaces and colloids.

[26]  J. C. Chen,et al.  Fast drop movements resulting from the phase change on a gradient surface. , 2001, Science.

[27]  P. Fischer,et al.  Controlled propulsion of artificial magnetic nanostructured propellers. , 2009, Nano letters.

[28]  D. Quéré,et al.  Self-propelling slugs , 2002, Journal of Fluid Mechanics.

[29]  H. Stark,et al.  Swimming active droplet: A theoretical analysis , 2012, 1210.2560.

[30]  Martin Pumera,et al.  Liquid-liquid interface motion of a capsule motor powered by the interlayer Marangoni effect. , 2012, The journal of physical chemistry. B.

[31]  V. Strelnikov,et al.  Robust Technique Allowing the Manufacture of Superoleophobic (Omniphobic) Metallic Surfaces , 2014 .

[32]  Oleg Gendelman,et al.  A floating self-propelling liquid marble containing aqueous ethanol solutions , 2015 .

[33]  G. Paul Neitzel,et al.  NONCOALESCENCE AND NONWETTING BEHAVIOR OF LIQUIDS , 2002 .

[34]  Martin Pumera,et al.  Marangoni self-propelled capsules in a maze: pollutants 'sense and act' in complex channel environments. , 2014, Lab on a chip.

[35]  R. Winkler,et al.  Physics of microswimmers—single particle motion and collective behavior: a review , 2014, Reports on progress in physics. Physical Society.