Microfluidic Pump Driven by Anisotropic Phoresis

Abstract

Fluid flow along microchannels can be induced by keeping opposite walls at different temperatures, and placing elongated tilted pillars inside the channel. The driving force for this fluid motion arises from the anisotropic thermophoretic effect of the elongated pillars that generates a force parallel to the walls, and perpendicular to the temperature gradient. The force is not determined by the thermophilic or thermophobic character of the obstacle surface, but by the geometry and the thermophoretic anisotropy of the obstacle. Via mesoscale hydrodynamic simulations, we investigate the pumping properties of the device as a function of the channel geometry, and pillar surface properties. Applications as fluidic mixers, and fluid alternators are also outlined, together with the potential use of all these devices to harvest waste heat energy. Furthermore, similar devices can be also built employing diffusiophoresis or electrophoresis. arXiv:1808.05028v2 [cond-mat.soft]

Obstacle-induced giant jammed aggregation of active semiflexible filaments

“…microfilaments/microtubules self-organizing in the cytoplasm, immune cells migrating in tissue, bacterial locomotion in soil, and application of selfpropelled particles in microfluidic devices, drug delivery or other biomedical operations. 1,[30][31][32][33][34] Hence, much research effort has been devoted to investigating the behavior of active objects in contact with obstacles. It is found that an active agent can be captured and trapped around a circular obstacle depending on the propelling mechanism and/or hydrodynamic or other alignment interactions.…”

Hydrodynamics of immiscible binary fluids with viscosity contrast: a multiparticle collision dynamics approach

“…10 Furthermore, the multiparticle collision dynamics (MPC) method, a particle-based hydrodynamic simulation approach which captures hydrodynamic interactions and thermal fluctuations, [11][12][13][14][15][16][17] has been proven valuable and efficient for mesoscale simulations, and has been applied in a broad range of studies of biological and active polymers, [18][19][20][21][22][23][24][25][26] colloids, [27][28][29][30][31] proteins, 32,33 vesicles and blood cells, 34,35 microswimmers, [36][37][38][39][40][41][42][43][44][45][46] and microfluidics. 47,48 To date, various MPC implementations of binary fluid mixtures have been proposed, and their phase behavior has been studied. [49][50][51][52][53][54][55]…”

Hydrodynamics of Immiscible Binary Fluids with Viscosity Contrast: A multiparticle collision dynamics approach

“…Dissipative particle dynamics (DPD) simulations, which explicitly account of conservative pair interactions between fluid particles, allow to realize multi-phase fluids via assigning distinct interactions between the particles [10]. Furthermore, the multiparticle collision dynamics (MPC) method, a particlebased hydrodynamic simulation approach which captures hydrodynamic interactions and thermal fluctuations [11][12][13][14][15][16][17], has been proven valuable and efficient for mesoscale simulations, and has been applied in a broad range of studies of biological and active polymers [18][19][20][21][22][23][24][25][26], colloids [27][28][29][30][31], proteins [32,33], vesicles and blood cells [34,35], microswimmers [36][37][38][39][40][41][42][43][44][45][46], and microfluidics [47,48]. To date, various MPC implementations of binary fluid mixtures have been proposed, and their phase behavior has * z.tan@fz-juelich.de been studied [49][50][51][52]…”