Jiachen Wei^1,2,*

Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 103-104, 2019, DOI:10.32604/mcb.2019.07721

Abstract Phoretic flow can be generated by different types of gradient (e.g. temperature, concentration, or charge gradient) [1-3]. Within micro-to-nano confined system, the diffusio-phoretic property for proteins differs dramatically from that obtained in bulk condition, due to concentration fluctuation that emerges at microscopic level induced by specific and nonspecific interactions between protein and co-solute [4-5]. The phoretic mobility of protein individuals and complex in solute gradients can be theoretically described by continuum model [1-2] that neglects microscopic heterogeneity and determined experimentally by microfluidics [6], but the underlying mechanism of diffusio-phoretic motion for confined protein still remains unclear.
Our approach to… More >

Sitong Zhou¹, Jiandi Wan^1,*

Molecular & Cellular Biomechanics, Vol.16, Suppl.2, pp. 70-70, 2019, DOI:10.32604/mcb.2019.06978

Abstract Piezo proteins (Piezo1 and Piezo2) are recently identified mechanically activated cation channels in eukaryotic cells and associated with physiological responses to touch, pressure, and stretch. In particular, human RBCs express Piezo1 on their membranes, and mutations of Piezo1 have been linked to hereditary xerocytosis. To date, however, physiological functions of Piezo1 on normal RBCs remain poorly understood. Here, we show that Piezo1 regulates mechanotransductive release of ATP from human RBCs by controlling the shear-induced Ca2+ influx [1]. We find that, in human RBCs treated with Piezo1 inhibitors or having mutant Piezo1 channels, the amounts of shear-induced ATP release and Ca2+… More >

Tawfiq Chekifi^{1, *}, Brahim Dennai², Rachid Khelfaoui²

FDMP-Fluid Dynamics & Materials Processing, Vol.13, No.3, pp. 173-187, 2017, DOI:10.3970/fdmp.2017.013.173

Abstract Recently, modeling immiscible fluids such as oil and water have been a classical research topic. Droplet-based microfluidics presents a unique platform for mixing, reaction, separation, dispersion of drops and many other functions. In this paper, we suggest a numerical CFD study of microfluidic oscillator with two different lengths of feedback loop. In order to produce simultaneous droplets of gasoil on water, a typical geometry that includes double T-junction is connected to the fluidic oscillator. Droplets production is computed by volume-of-fluid method (VOF). Flow oscillations of droplets were triggered by the Coanda effect of jet flow. The aim of work is… More >

Chih-Chang Chang, Ruey-Jen Yang¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.2, pp. 77-86, 2009, DOI:10.3970/icces.2009.010.077

Abstract This paper presents a theoretical investigation into chaotic mixing in low Reynolds number electro-osmotic flows. In this mixing system, the primary flow is the plug-like electro-osmotic flow contributed by the permanent surface charge at the wall, and the secondary electro-osmotic flows (or electro-osmotic recirculating rolls) contributed by the field-effect-induced surface charge act as the perturbed flow. By time-periodic switching two different secondary electro-osmotic flows, it makes streamlines to cross at successive intervals and results in chaotic mixing. Dynamic system techniques such as Poincaré map and finite-time Lyapunov exponent analyses are employed to describe the behaviors of particle motion in this… More >

David Azria^1,2, Raluca Guermache^1,2, Sophie Raisin¹, Sébastien Blanquer¹, Frédéric Gobeaux³, Marie Morille¹, Emmanuel Belamie^1,2,*

Journal of Renewable Materials, Vol.6, No.3, pp. 314-324, 2018, DOI:10.7569/JRM.2017.634186

Abstract Biopolymers extracted from renewable resources like chitosan and collagen exhibit interesting properties for the elaboration of materials designed for tissue engineering applications, among which are their hydrophilicity, biocompatibility and biodegradability. In many cases, functional recovery of an injured tissue or organ requires oriented cell outgrowth, which is particularly critical for nerve regeneration. Therefore, there is a growing interest for the elaboration of materials exhibiting functionalization gradients able to guide cells. Here, we explore an original way of elaborating such gradients by assembling particles from a library of functionalized microspheres. We propose a simple process to prepare chitosan-collagen hybrid microspheres by… More >

Z. Karakaya¹, B. Baranoğlu², B. Çetin³, A. Yazici⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.104, No.3, pp. 227-249, 2015, DOI:10.3970/cmes.2015.104.227

Abstract A new formulation for tracking multiple particles in slow viscous flow for microfluidic applications is presented. The method employs the manipulation of the boundary element matrices so that finally a system of equations is obtained relating the rigid body velocities of the particle to the forces applied on the particle. The formulation is specially designed for particle trajectory tracking and involves successive matrix multiplications for which SMP (Symmetric multiprocessing) parallelisation is applied. It is observed that present formulation offers an efficient numerical model to be used for particle tracking and can easily be extended for multiphysics simulations in which several… More >

Y. Inoue¹, R. Kobayashi¹, S. Ogata¹, T. Gotoh¹

CMES-Computer Modeling in Engineering & Sciences, Vol.63, No.2, pp. 137-162, 2010, DOI:10.3970/cmes.2010.063.137

Abstract Vibration of a single graphene and a pair of graphenes at micro meter scale induced by air flow is numerically simulated and examined by using a hybrid computational method starting from a microscopic level of description for the graphene. In order to bridge a huge gap in spatial and time scales in their motions, the carbon atoms of the graphene are represented by a small number of coarse grained particles, the fluid motion is described by the lattice Boltzmann equation and the momentum exchange at the boundary is treated by the time averaged immersed boundary method. It is found that… More >

Chekifi. T^1,2, Dennai. B¹, Khelfaoui. R¹

FDMP-Fluid Dynamics & Materials Processing, Vol.11, No.3, pp. 205-220, 2015, DOI:10.3970/fdmp.2015.011.205

Abstract Droplet generation, splitting and sorting are investigated numerically in the framework of a VOF technique for interface tracking and a finite-volume numerical method using the commercial code FLUENT. Droplets of water-in-oil are produced by a flow focusing technique relying on the use of a microchannell equipped with an obstacle to split the droplets. The influence of several parameters potentially affecting this process is investigated parametrically towards the end of identifying "optimal" conditions for droplet breakup. Such parameters include surface tension, the capillary number and the main channel width. We show that the capillary number plays a crucial role in determining… More >

Malcolm R. Davidson¹, Dalton J.E. Harvie¹

FDMP-Fluid Dynamics & Materials Processing, Vol.7, No.3, pp. 317-328, 2011, DOI:10.3970/fdmp.2011.007.317

Abstract A volume-of-fluid numerical method, adapted by the authors [Harvie, Cooper-White and Davidson (2008)] to simulate the flow of viscoelastic fluids, is used to predict deformation of a viscoelastic droplet carried by an immiscible Newtonian liquid through an axisymmetric microfluidic contraction-expansion. Values of the capillary number and elasticity number are chosen based on corresponding values for a rectangular contraction for which a reentrant cavity at the rear of the drop and subsequent encapsulation behaviour was observed experimentally by Harvie, Cooper-White and Davidson (2008). A reentrant cavity, similar to the observed one, is predicted; however, encapsulation is not achieved. Unexpectedly, a narrow… More >

V. Cristini¹, Y. Renardy²

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.2, pp. 77-94, 2006, DOI:10.3970/fdmp.2006.002.077

Abstract We review studies of a drop of viscous liquid, suspended in another liquid, and undergoing breakup in an impulsively started shear flow. Stokes flow conditions as well as the effects of inertia are reported. They reveal a universal scaling for the fragments, which allows one to use sheared emulsions to produce monodispersity as an alternative to microfluidic devices. More >