scholarly journals Dynamics of a Viscous Droplet in Return Bends of Microfluidic Channels

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
John-Luke Singh ◽  
Yechun Wang ◽  
Yan Zhang ◽  
Julie A. Melbye ◽  
Amanda E. Brooks ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Microfluidic Channels ◽  
Microfluidic Systems ◽  
Computational Framework ◽  
Operational Conditions ◽  
Fluid Properties ◽  
Droplet Trajectory ◽  
And Migration ◽  
Viscous Droplets ◽  
Viscous Droplet

Abstract Return bends are frequently encountered in microfluidic systems. In this study, a three-dimensional spectral boundary element method for interfacial dynamics in Stokes flow has been adopted to investigate the dynamics of viscous droplets in rectangular return bends. The droplet trajectory, deformation, and migration velocity are investigated under the influence of various fluid properties and operational conditions, which are depicted by the Capillary number, viscosity ratio, and droplet size, as well as the dimensions of the return bend. While the computational results provide information for the design of return bends in microfluidic systems in general, the computational framework shows potential to guide the design and operation of a droplet-based microfluidic delivery system for cell seeding.

Droplet Dynamics in Constricted Return Bends of Microfluidic Channels

2020 ◽  
Author(s):  
Julie A. Melbye ◽  
Yechun Wang
Keyword(s):  
High Throughput ◽  
Three Dimensional ◽  
Microfluidic Channels ◽  
Cell Seeding ◽  
Droplet Dynamics ◽  
Droplet Shape ◽  
Operational Conditions ◽  
Fluid Properties ◽  
Dimensional Boundary ◽  
And Migration

Abstract Microfluidic delivery systems have been employed to facilitate cell seeding procedures in drug development for personalized medicine for cancer patients. Despite of the high-throughput nature and potential impact on clinical outcomes of these systems, the efficiency in cell trapping remains a challenge in the operation. Droplet-based microfluidics became one of the solutions due to the large size of the cell-enclosing droplets and their interfacial properties. This study is focused on the motion of the cell-enclosing droplet in a constricted return bends that help to restrict the release of the cells while maintaining the high-throughput nature of the device. In this preliminary study, a three-dimensional boundary element method is used to predict droplet shape, deformation and migration velocity under the influence of various fluid properties and operational conditions. A variety of channel geometries have been explored as well. The resulting computational framework will be used to guide the design of a droplet-based microfluidic delivery system for cell seeding in 3D tumor spheroid arrays.

Viscous Droplet Interaction With Micro-Textured Solid Surfaces

2014 ◽  
Author(s):  
Kevin M. Beussman ◽  
Yechun Wang
Keyword(s):  
Relative Size ◽  
Three Dimensional ◽  
Bond Number ◽  
Industrial Applications ◽  
Solid Surfaces ◽  
Textured Surfaces ◽  
Droplet Motion ◽  
Materials Research ◽  
Viscous Droplets ◽  
Viscous Droplet

The dynamics of viscous droplets near solid surfaces, especially micro-textured surfaces, and the interaction between them are of great importance in industrial applications, biochemical processes, and fundamental materials research on surface wettability. In this work, a three-dimensional spectral boundary element method has been employed to investigate the dynamics of a viscous droplet falling under gravity influence to micro-textured solid surfaces. The droplet size, in this study, is comparable to the size of the surface texture. The influences of the Bond number, relative size of the droplet with respect to the surface features, and the topological characteristics of the substrate on the droplet motion and deformation are investigated. The stress exerted on the substrate due to droplet motion is also explored.

Dynamics of Viscous Droplets Falling Towards Micro-Patterned Solid Surfaces

2013 ◽  
Author(s):  
Kevin M. Beussman ◽  
Yechun Wang ◽  
Wei Y. Lim ◽  
Qixin Zhou
Keyword(s):  
Boundary Element Method ◽  
Three Dimensional ◽  
Bond Number ◽  
Industrial Applications ◽  
Solid Surfaces ◽  
Material Research ◽  
Biochemical Processes ◽  
Topological Features ◽  
Viscous Droplets ◽  
Viscous Droplet

The interaction between droplets and solid surfaces is of great importance in industrial applications, biochemical processes, and fundamental material research on surface wettability. In this work, a three-dimensional spectral boundary element method has been employed to investigate the dynamics of a viscous droplet falling under gravity influence to micro-patterned solid surfaces. The dynamics of the droplet are investigated under the influence of the Bond number and the topological features of the substrate.

scholarly journals A computational framework for modeling cell–matrix interactions in soft biological tissues

2021 ◽  
Author(s):  
Jonas F. Eichinger ◽  
Maximilian J. Grill ◽  
Iman Davoodi Kermani ◽  
Roland C. Aydin ◽  
Wolfgang A. Wall ◽  
...  
Keyword(s):  
Soft Tissues ◽  
Three Dimensional ◽  
Biological Tissues ◽  
Computational Framework ◽  
Cell Matrix ◽  
Physiological Processes ◽  
Matrix Interactions ◽  
Mechanical Homeostasis ◽  
Cell Matrix Interactions ◽  
Short Time

AbstractLiving soft tissues appear to promote the development and maintenance of a preferred mechanical state within a defined tolerance around a so-called set point. This phenomenon is often referred to as mechanical homeostasis. In contradiction to the prominent role of mechanical homeostasis in various (patho)physiological processes, its underlying micromechanical mechanisms acting on the level of individual cells and fibers remain poorly understood, especially how these mechanisms on the microscale lead to what we macroscopically call mechanical homeostasis. Here, we present a novel computational framework based on the finite element method that is constructed bottom up, that is, it models key mechanobiological mechanisms such as actin cytoskeleton contraction and molecular clutch behavior of individual cells interacting with a reconstructed three-dimensional extracellular fiber matrix. The framework reproduces many experimental observations regarding mechanical homeostasis on short time scales (hours), in which the deposition and degradation of extracellular matrix can largely be neglected. This model can serve as a systematic tool for future in silico studies of the origin of the numerous still unexplained experimental observations about mechanical homeostasis.

scholarly journals A flexible framework for sequential estimation of model parameters in computational hemodynamics

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Christopher J. Arthurs ◽  
Nan Xiao ◽  
Philippe Moireau ◽  
Tobias Schaeffter ◽  
C. Alberto Figueroa
Keyword(s):  
Unscented Kalman Filter ◽  
Three Dimensional ◽  
Synthetic Data ◽  
Sequential Estimation ◽  
Wall Material ◽  
Patient Specific ◽  
Model Parameters ◽  
Computational Framework ◽  
Lumped Parameter ◽  
Estimation Of Model Parameters

AbstractA major challenge in constructing three dimensional patient specific hemodynamic models is the calibration of model parameters to match patient data on flow, pressure, wall motion, etc. acquired in the clinic. Current workflows are manual and time-consuming. This work presents a flexible computational framework for model parameter estimation in cardiovascular flows that relies on the following fundamental contributions. (i) A Reduced-Order Unscented Kalman Filter (ROUKF) model for data assimilation for wall material and simple lumped parameter network (LPN) boundary condition model parameters. (ii) A constrained least squares augmentation (ROUKF-CLS) for more complex LPNs. (iii) A “Netlist” implementation, supporting easy filtering of parameters in such complex LPNs. The ROUKF algorithm is demonstrated using non-invasive patient-specific data on anatomy, flow and pressure from a healthy volunteer. The ROUKF-CLS algorithm is demonstrated using synthetic data on a coronary LPN. The methods described in this paper have been implemented as part of the CRIMSON hemodynamics software package.

Analysis of migration paths in fast-ion conductors with Voronoi–Dirichlet partition

2006 ◽  
Vol 62 (6) ◽  
pp. 1010-1018 ◽  
Author(s):  
Vladislav A. Blatov ◽  
Gregory D. Ilyushin ◽  
Olga A. Blatova ◽  
Nataly A. Anurova ◽  
Alexej K. Ivanov-Schits ◽  
...  
Keyword(s):  
Alkali Metals ◽  
Three Dimensional ◽  
Charge Carriers ◽  
Alkali Cations ◽  
Fast Ion Conductors ◽  
And Migration ◽  
Crystal Space ◽  
Fast Ion ◽  
Dirichlet Partition ◽  
Ion Conductors

In terms of the Voronoi–Dirichlet partition of the crystal space, definitions are given for such concepts as `void', `channel' and `migration path' for inorganic structures with three-dimensional networks of chemical bonds. A number of criteria are proposed for selecting significant voids and migration channels for alkali cations Li+–Cs+ based on the average characteristics of the Voronoi–Dirichlet polyhedra for alkali metals in oxygen-containing compounds. A general algorithm to analyze the voids in crystal structures has been developed and implemented in the computer package TOPOS. This approach was used to predict the positions of Li+ and Na+ cations and to analyze their possible migration paths in the solid superionic materials Li3 M 2P3O12 (M = Sc, Fe; LIPHOS) and Na1 + x Zr2Si x P3 − x O12 (NASICON), whose framework structures consist of connected M octahedra and T tetrahedra. Using this approach we determine the most probable places for charge carriers (coordinates of alkali cations) and the dimensionality of their conducting sublattice with high accuracy. The theoretically calculated coordinates of the alkali cations in MT frameworks are found to correlate to within 0.33 Å with experimental data for various phases of NASICON and LIPHOS. The proposed method of computer analysis is universal and suitable for investigating fast-ion conductors with other conducting components.

A Fluid-Structure Coupled Computational Framework for Fluid-Induced Failure and Fracture

2015 ◽  
Author(s):  
Patrick D. Lea ◽  
Charbel Farhat ◽  
Kevin G. Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Extended Finite Element Method ◽  
Three Dimensional ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Extended Finite Element ◽  
Computational Framework ◽  
Fluid Structure ◽  
Fracture Models

This work extends and generalizes a recently developed fluid-structure coupled computational framework to model and simulate fluid-induced failure and fracture. In particular, a novel surface representation approach is proposed to represent a fractured fluid-structure interface in the context of embedded boundary method. This approach is generic in the sense that it is applicable to many different computational fracture models and methods, including the element deletion (ED) technique and the extended finite element method (XFEM). Two three-dimensional model problems are presented to demonstrate the salient features of the computational framework, and to compare the performance of ED and XFEM in the context of fluid-induced failure and fracture.

scholarly journals Morpholithodynamics of lagoonal straits of the North-Eastern Sakhalin

2019 ◽  
pp. 79-94
Author(s):  
V. V. Afanasev
Keyword(s):  
Additional Data ◽  
Three Dimensional ◽  
Remote Sensing Data ◽  
Water Area ◽  
The North ◽  
North Eastern ◽  
Geological Information ◽  
History Of ◽  
Three Dimensional Models ◽  
And Migration

The results of the analysis of geospatial and geological information on the structure and dynamics of the lagoon coast of the North-Eastern Sakhalin are presented. On the basis of a number of parameters of the coastal erosion-accumulation processes and migration of lagoon straits during the period 1927–2014. the morpholithodynamics system of the North-Eastern Sakhalin was considered. The volume of sediments transported during the migration of the straits, was estimated with the help of three-dimensional models, in which, parallel with time-averaged areas of erosion and accumulation, additional data were used, namely: bathymetry of the straits and adjacent water area, characteristics of the relief of the barrier forms and geological information obtained as a result of georadar survey and drilling. Georadar data, together with remote sensing data, have made it possible to create a model of sedimentation, which formed the basis for the analysis of the history of the coast formation beyond the period of observations. Currently, we can trace the situation as long as to the middle of the XIXth century.

scholarly journals Application of microfluidic systems for neural differentiation of cells

2019 ◽  
Vol 2 (4) ◽  
pp. 370-381
Author(s):  
Zahra Hesari ◽  
Fatemeh Mottaghitalab ◽  
Akram Shafiee ◽  
Masoud Soleymani ◽  
Rasoul Dinarvand ◽  
...  
Keyword(s):  
Stem Cells ◽  
Small Molecules ◽  
Neuronal Differentiation ◽  
Neural Differentiation ◽  
Three Dimensional ◽  
Microfluidic System ◽  
Microfluidic Systems ◽  
Cell Culture Systems ◽  
Novel Model ◽  
Dimensional Cell

Neural differentiation of stem cells is an important issue in development of central nervous system. Different methods such as chemical stimulation with small molecules, scaffolds, and microRNA can be used for inducing the differentiation of neural stem cells. However, microfluidic systems with the potential to induce neuronal differentiation have established their reputation in the field of regenerative medicine. Organization of microfluidic system represents a novel model that mimic the physiologic microenvironment of cells among other two and three dimensional cell culture systems. Microfluidic system has patterned and well-organized structure that can be combined with other differentiation techniques to provide optimal conditions for neuronal differentiation of stem cells. In this review, different methods for effective differentiation of stem cells to neuronal cells are summarized. The efficacy of microfluidic systems in promoting neuronal differentiation is also addressed.

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