Boundaries can steer active Janus spheres

The advent of autonomous self-propulsion has instigated research towards making colloidal machines that can deliver mechanical work in the form of transport, and other functions such as sensing and cleaning. While much progress has been made in the last 10 years on various mechanisms to generate self-propulsion, the ability to steer self-propelled colloidal devices has so far been much more limited. A critical barrier in increasing the impact of such motors is in directing their motion against the Brownian rotation, which randomizes particle orientations. In this context, here we report directed motion of a specific class of catalytic motors when moving in close proximity to solid surfaces. This is achieved through active quenching of their Brownian rotation by constraining it in a rotational well, caused not by equilibrium, but by hydrodynamic effects. We demonstrate how combining these geometric constraints can be utilized to steer these active colloids along arbitrary trajectories.

[1]  Effect of a finite half-width on combined electroosmosis-electrophoresis measurements in a rectangular cell , 1981 .

[2]  Stephen J. Ebbens,et al.  In pursuit of propulsion at the nanoscale , 2010 .

[3]  Wei Wang,et al.  Small power: Autonomous nano- and micromotors propelled by self-generated gradients , 2013 .

[4]  R. G. Cox,et al.  Slow viscous motion of a sphere parallel to a plane wall , 1967 .

[5]  Gary J. Dunderdale,et al.  Electrokinetic effects in catalytic platinum-insulator Janus swimmers , 2013, 1312.6250.

[6]  Samuel Sanchez,et al.  Chemotactic behavior of catalytic motors in microfluidic channels. , 2013, Angewandte Chemie.

[7]  Ramin Golestanian,et al.  Propulsion of a molecular machine by asymmetric distribution of reaction products. , 2005, Physical review letters.

[8]  Joseph Wang,et al.  Cargo-towing synthetic nanomachines: towards active transport in microchip devices. , 2012, Lab on a chip.

[9]  W. Xi,et al.  Self-propelled nanotools. , 2012, ACS nano.

[10]  R Di Leonardo,et al.  Hydrodynamic Trapping of Swimming Bacteria by Convex Walls. , 2015, Physical review letters.

[11]  Sumit Gangwal,et al.  Dielectrophoretic assembly of metallodielectric Janus particles in AC electric fields. , 2008, Langmuir : the ACS journal of surfaces and colloids.

[12]  D. Velegol,et al.  Localized electroosmosis (LEO) induced by spherical colloidal motors. , 2014, Langmuir : the ACS journal of surfaces and colloids.

[13]  M. Yoda,et al.  Measurements of the near-wall hindered diffusion of colloidal particles in the presence of an electric field , 2011 .

[14]  Enrique García Jordá.  Fantastic voyage , 2009, Clinical & translational oncology : official publication of the Federation of Spanish Oncology Societies and of the National Cancer Institute of Mexico.

[15]  Wall effects on self-diffusiophoretic Janus particles: a theoretical study , 2013, Journal of Fluid Mechanics.

[16]  John L. Anderson,et al.  Effect of nonuniform zeta potential on particle movement in electric fields , 1985 .

[17]  Samuel Sanchez,et al.  Catalytic Janus motors on microfluidic chip: deterministic motion for targeted cargo delivery. , 2012, ACS nano.

[18]  Ramin Golestanian,et al.  Size dependence of the propulsion velocity for catalytic Janus-sphere swimmers. , 2012, Physical review. E, Statistical, nonlinear, and soft matter physics.

[19]  Ryan Pavlick,et al.  Intelligent, self-powered, drug delivery systems. , 2013, Nanoscale.

[20]  S. Ramaswamy,et al.  Clusters, asters, and collective oscillations in chemotactic colloids. , 2013, Physical review. E, Statistical, nonlinear, and soft matter physics.

[21]  H. Brenner,et al.  Near-contact electrophoretic motion of a sphere parallel to a planar wall , 2003, Journal of Fluid Mechanics.

[22]  J. Howse,et al.  Direct observation of the direction of motion for spherical catalytic swimmers. , 2011, Langmuir : the ACS journal of surfaces and colloids.

[23]  Lluís Soler,et al.  Catalytic nanomotors for environmental monitoring and water remediation , 2014, Nanoscale.

[24]  Jeffrey N. Anker,et al.  Metal-Capped Brownian and Magnetically Modulated Optical Nanoprobes (MOONs): Micromechanics in Chemical and Biological Microenvironments† , 2004 .

[25]  R. Golestanian,et al.  Designing phoretic micro- and nano-swimmers , 2007, cond-mat/0701168.

[26]  G. Gompper,et al.  Hydrodynamics of sperm cells near surfaces. , 2010, Biophysical journal.

[27]  Jonathan D Posner,et al.  Rapid fabrication of bimetallic spherical motors. , 2010, Langmuir : the ACS journal of surfaces and colloids.

[28]  Wilson Poon,et al.  Ionic effects in self-propelled Pt-coated Janus swimmers. , 2013, Soft matter.

[29]  Juliane Simmchen,et al.  Asymmetric hybrid silica nanomotors for capture and cargo transport: towards a novel motion-based DNA sensor. , 2012, Small.

[30]  F. Jülicher,et al.  Generic theory of colloidal transport , 2008, The European physical journal. E, Soft matter.

[31]  Ramin Golestanian,et al.  Anomalous diffusion of symmetric and asymmetric active colloids. , 2009, Physical review letters.

[32]  Siyoung Q. Choi,et al.  Synthesis of Multifunctional Micrometer‐Sized Particles with Magnetic, Amphiphilic, and Anisotropic Properties , 2011, Advanced materials.

[33]  S. Balasubramanian,et al.  Chemical sensing based on catalytic nanomotors: motion-based detection of trace silver. , 2009, Journal of the American Chemical Society.

[34]  E. Lauga,et al.  Hydrodynamics of self-propulsion near a boundary: predictions and accuracy of far-field approximations , 2012, Journal of Fluid Mechanics.

[35]  M. Manjare,et al.  Bubble driven quasioscillatory translational motion of catalytic micromotors. , 2012, Physical review letters.

[36]  G. Morfill,et al.  Simple estimation of thermodynamic properties of Yukawa systems. , 2014, Physical review. E, Statistical, nonlinear, and soft matter physics.

[37]  Juho S. Lintuvuori,et al.  Swimming in a Crystal: Hydrodynamic, Phoretic and Steric Interactions , 2014 .

[38]  Jonathan Howse,et al.  Importance of particle tracking and calculating the mean-squared displacement in distinguishing nanopropulsion from other processes. , 2012, Langmuir : the ACS journal of surfaces and colloids.

[39]  Darrell Velegol,et al.  Enhanced transport into and out of dead-end pores. , 2015, ACS nano.

[40]  Ayusman Sen,et al.  Catalytic motors for transport of colloidal cargo. , 2008, Nano letters.

[41]  J Cranshaw,et al.  Search for excited and exotic electrons in the egamma decay channel in pp collisions at sqrt[s] = 1.96 TeV. , 2005, Physical review letters.

[42]  B. A. Brown,et al.  Mass measurements of the neutron-deficient 41Ti, 45Cr, 49Fe, and 53Ni nuclides: first test of the isobaric multiplet mass equation in f p-shell nuclei. , 2012, Physical review letters.

[43]  Hartmut Löwen,et al.  Gravitaxis of asymmetric self-propelled colloidal particles , 2014, Nature Communications.

[44]  Stephen J. Ebbens,et al.  Gravitaxis in Spherical Janus Swimming Devices , 2013, Langmuir : the ACS journal of surfaces and colloids.

[45]  Ramin Golestanian,et al.  Self-motile colloidal particles: from directed propulsion to random walk. , 2007, Physical review letters.

[46]  John L. Ande,et al.  COLLOID TRANSPORT BY INTERFACIAL FORCES , 1989 .

[47]  T. Mallouk,et al.  Bipolar electrochemical mechanism for the propulsion of catalytic nanomotors in hydrogen peroxide solutions. , 2006, Langmuir : the ACS journal of surfaces and colloids.

[48]  Yang Wang,et al.  Catalytically induced electrokinetics for motors and micropumps. , 2006, Journal of the American Chemical Society.

[49]  M. Tasinkevych,et al.  Self-propulsion of a catalytically active particle near a planar wall: from reflection to sliding and hovering. , 2014, Soft matter.

[50]  George M Whitesides,et al.  Swimming in circles: motion of bacteria near solid boundaries. , 2005, Biophysical journal.