scholarly journals Preparation of monodisperse hybrid gel particles with various morphologies via flow rate and temperature control

Soft Matter ◽  
2019 ◽  
Vol 15 (35) ◽  
pp. 6934-6937 ◽  
Author(s):  
Toshimitsu Kanai ◽  
Hiroki Nakai ◽  
Ayaka Yamada ◽  
Masafumi Fukuyama ◽  
David A. Weitz
Keyword(s):  
Temperature Control ◽  
Flow Rate ◽  
Microfluidic Devices ◽  
Hybrid Gel ◽  
Gel Particles

We report a facile method for preparing monodisperse hybrid smart gel particles with various morphologies by using microfluidic devices.

scholarly journals A Numerical Study of Sub-Millisecond Integrated Mix-and-Inject Microfluidic Devices for Sample Delivery at Synchrotron and XFELs

2021 ◽  
Vol 11 (8) ◽  
pp. 3404
Author(s):  
Majid Hejazian ◽  
Eugeniu Balaur ◽  
Brian Abbey
Keyword(s):  
Molecular Dynamics ◽  
Flow Rate ◽  
Numerical Study ◽  
Three Dimensional ◽  
Microfluidic Devices ◽  
Liquid Jets ◽  
Mixing Efficiency ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
Time Required

Microfluidic devices which integrate both rapid mixing and liquid jetting for sample delivery are an emerging solution for studying molecular dynamics via X-ray diffraction. Here we use finite element modelling to investigate the efficiency and time-resolution achievable using microfluidic mixers within the parameter range required for producing stable liquid jets. Three-dimensional simulations, validated by experimental data, are used to determine the velocity and concentration distribution within these devices. The results show that by adopting a serpentine geometry, it is possible to induce chaotic mixing, which effectively reduces the time required to achieve a homogeneous mixture for sample delivery. Further, we investigate the effect of flow rate and the mixer microchannel size on the mixing efficiency and minimum time required for complete mixing of the two solutions whilst maintaining a stable jet. In general, we find that the smaller the cross-sectional area of the mixer microchannel, the shorter the time needed to achieve homogeneous mixing for a given flow rate. The results of these simulations will form the basis for optimised designs enabling the study of molecular dynamics occurring on millisecond timescales using integrated mix-and-inject microfluidic devices.

scholarly journals Heterogeneous Bonding of PMMA and Double-Sided Polished Silicon Wafers through H2O Plasma Treatment for Microfluidic Devices

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 580
Author(s):  
Chao-Ching Chiang ◽  
Philip Nathaniel Immanuel ◽  
Yi-Hsiung Chiu ◽  
Song-Jeng Huang
Keyword(s):  
Plasma Treatment ◽  
Flow Rate ◽  
Gas Flow ◽  
Treatment Time ◽  
Optical Emission ◽  
Microfluidic Devices ◽  
Oh Radicals ◽  
Gas Flow Rate ◽  
Oh Groups ◽  
Plasma Treatment Time

In this work we report on a rapid, easy-to-operate, lossless, room temperature heterogeneous H2O plasma treatment process for the bonding of poly(methyl methacrylate) (PMMA) and double-sided polished (DSP) silicon substrates by for utilization in sandwich structured microfluidic devices. The heterogeneous bonding of the sandwich structure produced by the H2O plasma is analyzed, and the effect of heterogeneous bonding of free radicals and high charge electrons (e−) in the formed plasma which causes a passivation phenomenon during the bonding process investigated. The PMMA and silicon surface treatments were performed at a constant radio frequency (RF) power and H2O flow rate. Changing plasma treatment time and powers for both processes were investigated during the experiments. The gas flow rate was controlled to cause ionization of plasma and the dissociation of water vapor from hydrogen (H) atoms and hydroxyl (OH) bonds, as confirmed by optical emission spectroscopy (OES). The OES results show the relative intensity peaks emitted by the OH radicals, H and oxygen (O). The free energy is proportional to the plasma treatment power and gas flow rate with H bonds forming between the adsorbed H2O and OH groups. The gas density generated saturated bonds at the interface, and the discharge energy that strengthened the OH-e− bonds. This method provides an ideal heterogeneous bonding technique which can be used to manufacture new types of microfluidic devices.

scholarly journals Volumetric flow rate in simulations of microfluidic devices

2018 ◽  
Vol 180 ◽  
pp. 02046
Author(s):  
KristÍna Kovalčíková ◽  
Martin Slavík ◽  
Katarína Bachratá ◽  
Hynek Bachratý ◽  
Alžbeta Bohiniková
Keyword(s):  
External Force ◽  
Flow Rate ◽  
Laboratory Experiments ◽  
Fluid Velocity ◽  
Volumetric Flow Rate ◽  
Microfluidic Devices ◽  
Fixed Set ◽  
Volumetric Rate ◽  
Simulation Parameter ◽  
Set Up

In this work, we examine the volumetric flow rate of microfluidic devices. The volumetric flow rate is a parameter which is necessary to correctly set up a simulation of a real device and to check the conformity of a simulation and a laboratory experiments [1]. Instead of defining the volumetric rate at the beginning as a simulation parameter, a parameter of external force is set. The proposed hypothesis is that for a fixed set of other parameters (topology, viscosity of the liquid, …) the volumetric flow rate is linearly dependent on external force in typical ranges of fluid velocity used in our simulations. To confirm this linearity hypothesis and to find numerical limits of this approach, we test several values of the external force parameter. The tests are designed for three different topologies of simulation box and for various haematocrits. The topologies of the microfluidic devices are inspired by existing laboratory experiments [3 - 6]. The linear relationship between the external force and the volumetric flow rate is verified in orders of magnitudes similar to the values obtained from laboratory experiments.

Vision-Based Real-Time Microflow-Rate Control System for Cell Analysis

2016 ◽  
Vol 28 (6) ◽  
pp. 854-861 ◽  
Author(s):  
Tadayoshi Aoyama ◽  
◽  
Amalka De Zoysa ◽  
Qingyi Gu ◽  
Takeshi Takaki ◽  
...  
Keyword(s):  
Fluid Flow ◽  
Control System ◽  
Real Time ◽  
Flow Rate ◽  
Rate Control ◽  
Microfluidic Devices ◽  
Cell Analysis ◽  
Time Flow ◽  
On Chip ◽  
Flow Rate Control

[abstFig src='/00280006/09.jpg' width='300' text='Snapshots of particle sorting experiment using our system' ] On-chip cell analysis is an important issue for microtechnology research, and microfluidic devices are frequently used in on-chip cell analysis systems. One approach to controlling the fluid flow in microfluidic devices for cell analysis is to use a suitable pumps. However, it is difficult to control the actual flow-rate in a microfluidic device because of the difficulty in placing flow-rate sensors in the device. In this study, we developed a real-time flow-rate control system that uses syringe pumps and high-speed vision to measure the actual fluid flow in microfluidic devices. The developed flow-rate control system was verified through experiments on microparticle velocity control and microparticle sorting.

Bubble Removal in Microfluidic Devices Using Nanofibrous Membranes

2014 ◽  
Author(s):  
Ravindra Vundavilli ◽  
Jeff Darabi
Keyword(s):  
Pore Size ◽  
Flow Rate ◽  
Liquid Flow ◽  
Liquid Flow Rate ◽  
Microfluidic Devices ◽  
Channel Height ◽  
Hydrophobic Membrane ◽  
Fluidic Channel ◽  
Nanofibrous Membranes ◽  
Bubble Removal

This paper presents an experimental study to determine bubble removal characteristics of nanofibrous membranes in microfluidic devices. It is well known that the presence of gas bubbles in fluidic channels can cause significant flow disturbances and adversely affect the overall performance and operation of microfluidic devices. In this study, a microfluidic device is designed and fabricated to generate and extract bubbles from a microfluidic channel. A T-junction is used to produce controllable bubbles at the entrance of fluidic channel. The generated bubbles are then transported to a bubble removal region and vented through a highly porous hydrophobic membrane. Four different hydrophobic PTFE membranes with different pore sizes ranging from 0.45 to 3 μm were used to permeate air bubbles. The fluidic channel width was 500 μm and channel height ranged from 100 to 300 μm. The effects of pore size, channel height, and liquid flow rate on the bubble removal rate are investigated. The results reveal that the rate of bubble removal increases with increasing the pore size and channel height but decreases with increasing the liquid flow rate.

Characteristics of Temperature Control by Hot-gas Bypass Flow Rate on Industrial Water Cooler

2009 ◽  
Vol 33 (8) ◽  
pp. 1129-1136 ◽  
Author(s):  
Seung-Moon Baek ◽  
Jun-Hyuk Choi ◽  
Jong-Yeong Byun ◽  
Choon-Geun Moon ◽  
Ho-Saeng Lee ◽  
...  
Keyword(s):  
Temperature Control ◽  
Flow Rate ◽  
Industrial Water ◽  
Bypass Flow ◽  
Hot Gas ◽  
Water Cooler

Chemical and physical processes for integrated temperature control in microfluidic devices

Lab on a Chip ◽  
2003 ◽  
Vol 3 (1) ◽  
pp. 1 ◽  
Author(s):  
Rosanne M. Guijt ◽  
Arash Dodge ◽  
Gijs W. K. van Dedem ◽  
Nico F. de Rooij ◽  
Elisabeth Verpoorte
Keyword(s):  
Temperature Control ◽  
Microfluidic Devices ◽  
Physical Processes
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