scholarly journals Modular pumps as programmable hydraulic batteries for microfluidic devices

TECHNOLOGY ◽  
2017 ◽  
Vol 05 (01) ◽  
pp. 21-30 ◽  
Author(s):  
Brian M. Cummins ◽  
Rukesh Chinthapatla ◽  
Balaji Lenin ◽  
Frances S. Ligler ◽  
Glenn M. Walker
Keyword(s):  
Microfluidic Device ◽  
Microfluidic Channel ◽  
Microfluidic Devices ◽  
Complex Flow ◽  
Oscillating Flows ◽  
Flow Rates ◽  
Simple Fluid ◽  
Flow Profiles ◽  
Over Time

Simple fluid pumps have been developed to improve microfluidic device portability, but they cannot be easily programmed, produce repeatable pumping performance, or generate complex flow profiles — key requirements for increasing the functionality of portable microdevices. We present a detachable, paper-based, “hydraulic battery” that can be connected to the outlet of a microfluidic channel to pump fluid at varying flow rates over time, including step changes, ramping flows, and oscillating flows.

A Multifunctional Microfluidic Device Based on Bifurcation Geometry

2010 ◽  
Author(s):  
Ahmed Fadl ◽  
Stefanie Demming ◽  
Zongqin Zhang ◽  
Bjo¨rn Hoxhold ◽  
Stephanus Bu¨ttgenbach ◽  
...  
Keyword(s):  
Microfluidic Device ◽  
Microfluidic Devices ◽  
Optical Lithography ◽  
Working Fluid ◽  
The Novel ◽  
Flow Rates ◽  
Single Function ◽  
Fluidic Device ◽  
Bifurcation Structures ◽  
Novel Design

Developing multifunctional devices are essential to realize more efficient Microsystems. With miniaturization processes taking place in many different applications, the rooms for single function microfluidic devices are limited. In this study, we introduce a multifunctional micro fluidic device based on bifurcation geometry which is capable of performing pumping and mixing at the same time. Optical lithography is used to fabricate the designed microfluidic device. The microfluidic device is tested at low actuator frequencies, and ethanol is employed as a working fluid. The operational principles are based on rectifying the oscillatory flows by using bifurcation structures for flow rectification. The results prove the feasibility of the novel design, and results are presented in terms of flow rates and maximum back pressures.

scholarly journals Autonomous and complex flow control involving multistep injection and liquid replacement in a reaction chamber on steadily rotating centrifugal microfluidic devices

RSC Advances ◽  
2017 ◽  
Vol 7 (57) ◽  
pp. 35869-35874 ◽  
Author(s):  
Shunya Okamoto ◽  
Yoshiaki Ukita
Keyword(s):  
Flow Control ◽  
Microfluidic Device ◽  
Microfluidic Devices ◽  
Reaction Chamber ◽  
Control Technique ◽  
Complex Flow

This study demonstrates a novel autonomous flow-control technique using siphon-shaped microchannels on a steadily rotating centrifugal microfluidic device.

scholarly journals Elasto-Magnetic Pumps Integrated within Microfluidic Devices

2021 ◽  
Vol 4 (1) ◽  
pp. 48
Author(s):  
Jacob L. Binsley ◽  
Elizabeth L. Martin ◽  
Thomas O. Myers ◽  
Stefano Pagliara ◽  
Feodor Y. Ogrin
Keyword(s):  
Magnetic System ◽  
Point Of Care ◽  
Microfluidic Channel ◽  
Lab On A Chip ◽  
Microfluidic Devices ◽  
Point Of Care Testing ◽  
Ongoing Research ◽  
Flow Rates ◽  
Pumping System ◽  
Oscillating Magnetic Field

Many lab-on-a-chip devices require a connection to an external pumping system in order to perform their function. While this is not problematic in typical laboratory environments, it is not always practical when applied to point-of-care testing, which is best utilized outside of the laboratory. Therefore, there has been a large amount of ongoing research into producing integrated microfluidic components capable of generating effective fluid flow from on-board the device. This research aims to introduce a system that can produce practical flow rates, and be easily fabricated and actuated using readily available techniques and materials. We show how an asymmetric elasto-magnetic system, inspired by Purcell’s three-link swimmer, can provide this solution through the generation of non-reciprocal motion in an enclosed environment. The device is fabricated monolithically within a microfluidic channel at the time of manufacture, and is actuated using a weak, oscillating magnetic field. The flow rate can be altered dynamically, and the direction of the resultant flow can be controlled by adjusting the frequency of the driving field. The device has been proven, experimentally and numerically, to operate effectively when applied to fluids with a range of viscosities. Such a device may be able to replace external pumping systems in portable applications.

Evaluation of Heat Transfer Performance of a Spiral Microfluidic Heatsink and Heat Exchanger Device

2018 ◽  
Author(s):  
Niven Singh Virik ◽  
Samuel D. Marshall ◽  
Rerngchai Arayanarakool ◽  
Hian Hian See ◽  
Heng Wang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Thermal Performance ◽  
Heat Sink ◽  
High Efficiency ◽  
Microfluidic Channel ◽  
Microfluidic Devices ◽  
Flow Rates ◽  
Dean Vortices ◽  
Number Of Layers

Developments in micro-technology have seen vast improvements in the design and the thermal performance of heat sinks and heat exchangers, particularly in the case of spiral microfluidic devices which deals with the flow of liquids inside curved micrometer-sized channels. The current research deals with a specially designed curved microfluidic channel used to employ the fluid mixing characteristics of Dean vortices and thus transfer heat more efficiently. This curved microfluidic channel is deployed as a spiral channel to create an effective heat sink and a heat exchanger. The novel micro heat exchanger is built by integrating two or more of the specially designed microfluidic heat sink layers. For the ease of fabricating the microchannels, these devices are polymer-based. In this paper, the thermal performance of the spiral microfluidic devices is analyzed numerically and experimentally using a range of flow rates where Thermal Performance Factor is used to find a balanced point between heat transfer and pressure drop. The spiral heat exchange device proves to be an effective thermal transport system with the introduction of curved channels in the devices where the presence of Dean vortices in the system is observed, especially at lower flow rates. It can be observed that by increasing the number of layers, the thermal performance is greatly improved. This is due to the higher surface area with increasing number of layers, as well as a parallel flow structure through the layers. These results serve as a design parameter for developing microchannel-based heat transfer devices that can achieve high efficiency of heat and mass transfer. Further heat sink and heat exchanger design improvements are discussed.

scholarly journals A Passive Microfluidic Device for Chemotaxis Studies

Micromachines ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 551 ◽  
Author(s):  
Maria Laura Coluccio ◽  
Maria Antonia D’Attimo ◽  
Costanza Maria Cristiani ◽  
Patrizio Candeloro ◽  
Elvira Parrotta ◽  
...  
Keyword(s):  
Cell Migration ◽  
Microfluidic Device ◽  
Cell Biology ◽  
Scientific Literature ◽  
Microfluidic Devices ◽  
Microfluidic System ◽  
Micro Milling ◽  
Flow Rates ◽  
Free Environment ◽  
Liquid Flows

This work presents a disposable passive microfluidic system, allowing chemotaxis studies, through the generation of a concentration gradient. The device can handle liquid flows without an external supply of pressure or electric gradients, but simply using gravity force. It is able to ensure flow rates of 10 µL/h decreasing linearly with 2.5% in 24 h. The device is made of poly(methylmethacrylate) (PMMA), a biocompatible material, and it is fabricated by micro-milling and solvent assisted bonding. It is assembled into a mini incubator, designed properly for cell biology studies in passive microfluidic devices, which provides control of temperature and humidity levels, a contamination-free environment for cells with air and 5% of CO2. Furthermore, the mini incubator can be mounted on standard inverted optical microscopes. By using our microfluidic device integrated into the mini incubator, we are able to evaluate and follow in real-time the migration of any cell line to a chemotactic agent. The device is validated by showing cell migration at a rate of 0.36 µm/min, comparable with the rates present in scientific literature.

scholarly journals Differential Sorting of Microparticles Using Spiral Microchannels with Elliptic Configurations

Micromachines ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 412
Author(s):  
Kaan Erdem ◽  
Vahid Ebrahimpour Ahmadi ◽  
Ali Kosar ◽  
Lütfullah Kuddusi
Keyword(s):  
Cell Sorting ◽  
Microfluidic Channel ◽  
Major Axis ◽  
Label Free ◽  
Flow Rates ◽  
Inertial Focusing ◽  
Size Dependent ◽  
Curved Channels ◽  
Aspect Ratios ◽  
Dependent Cell

Label-free, size-dependent cell-sorting applications based on inertial focusing phenomena have attracted much interest during the last decade. The separation capability heavily depends on the precision of microparticle focusing. In this study, five-loop spiral microchannels with a height of 90 µm and a width of 500 µm are introduced. Unlike their original spiral counterparts, these channels have elliptic configurations of varying initial aspect ratios, namely major axis to minor axis ratios of 3:2, 11:9, 9:11, and 2:3. Accordingly, the curvature of these configurations increases in a curvilinear manner through the channel. The effects of the alternating curvature and channel Reynolds number on the focusing of fluorescent microparticles with sizes of 10 and 20 µm in the prepared suspensions were investigated. At volumetric flow rates between 0.5 and 3.5 mL/min (allowing separation), each channel was tested to collect samples at the designated outlets. Then, these samples were analyzed by counting the particles. These curved channels were capable of separating 20 and 10 µm particles with total yields up to approximately 95% and 90%, respectively. The results exhibited that the level of enrichment and the focusing behavior of the proposed configurations are promising compared to the existing microfluidic channel configurations.

Magnetophoresis ‘meets’ viscoelasticity: deterministic separation of magnetic particles in a modular microfluidic device

Lab on a Chip ◽  
2015 ◽  
Vol 15 (8) ◽  
pp. 1912-1922 ◽  
Author(s):  
Francesco Del Giudice ◽  
Hojjat Madadi ◽  
Massimiliano M. Villone ◽  
Gaetano D'Avino ◽  
Angela M. Cusano ◽  
...  
Keyword(s):  
Microfluidic Device ◽  
Magnetic Particles ◽  
Magnetic Beads ◽  
Microfluidic Channel

Deflection of magnetic beads in a microfluidic channel can be improved through viscoelastic focusing.

scholarly journals A Sensitive Chemotaxis Assay Using a Novel Microfluidic Device

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Chen Zhang ◽  
Sunyoung Jang ◽  
Ovid C. Amadi ◽  
Koichi Shimizu ◽  
Richard T. Lee ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Microfluidic Device ◽  
Muscle Cells ◽  
Random Motion ◽  
Cellular Migration ◽  
Sensitive Assay ◽  
Chemotaxis Assay ◽  
Chemokine Gradient ◽  
Over Time

Existing chemotaxis assays do not generate stable chemotactic gradients and thus—over time—functionally measure only nonspecific random motion (chemokinesis). In comparison, microfluidic technology has the capacity to generate a tightly controlled microenvironment that can be stably maintained for extended periods of time and is, therefore, amenable to adaptation for assaying chemotaxis. We describe here a novel microfluidic device for sensitive assay of cellular migration and show its application for evaluating the chemotaxis of smooth muscle cells in a chemokine gradient.

TRANSFORMING THE CHARACTER OF THE UPPER MISSISSIPPI RIVER

2021 ◽  
Vol 40 (1) ◽  
pp. 102-129
Author(s):  
KRISTAN COCKERILL
Keyword(s):  
Nineteenth Century ◽  
Seventeenth Century ◽  
Mississippi River ◽  
River Management ◽  
Late Nineteenth Century ◽  
Upper Mississippi River ◽  
Flow Rates ◽  
Specific Language ◽  
Late Nineteenth ◽  
Over Time

ABSTRACT Despite the long-understood variability in the Mississippi River, the upper portions of the river have historically received less attention than the lower reach and this culminated in the lower river dominating twentieth century river management efforts. Since the seventeenth century, there have been multiple tendencies in how the upper river was characterized, including relatively spare notes about basic conditions such as channel width and flow rates which shifted to an emphasis on romantic descriptions of the riparian scenery by the mid-nineteenth century. Finally, by the late nineteenth century the upper river was routinely portrayed as a flawed entity requiring human intervention to fix it. While the tone and specific language changed over time, there remained a consistent emphasis that whatever was being reported about the river was scientifically accurate.

scholarly journals Metrological performance of single-jet water meters over time

2018 ◽  
Vol 13 (5) ◽  
pp. 1
Author(s):  
Carmen Virginia Palau ◽  
Juan Manzano ◽  
Iban Balbastre Peralta ◽  
Benito Moreira de Azevedo ◽  
Guilherme Vieira do Bomfim
Keyword(s):  
Measurement Error ◽  
Water Consumption ◽  
Operating Conditions ◽  
Economic Losses ◽  
Flow Rates ◽  
Metrological Operation ◽  
Operation Period ◽  
Single Jet ◽  
Water Meters ◽  
Over Time

To maintain quality measurement of water consumption, it is necessary to know the metrology of single-jet water meters over time. Knowing the accuracy of these instruments over time allows establishing a metrological operation period for different flow rates. This will aid water companies to optimize management and reduce economic losses due to unaccounted water consumption. This study analyzed the influence of time on the measurement error of single-jet water meters to evaluate the deterioration of the equipment and, with that, launch the metrological operation period. According to standards 8316 and 4064 of the International Organization for Standardization (ISO), 808 meters of metrological Class B were evaluated in six water supplies, with age ranges of 3.7 to 16.4 years of use. The measurement error was estimated by comparing the volume measured in a calibrated tank with the volume registered by the meters at flow rates of 30, 120, 750 and 1,500 L h-1. The metrological operation period of the meters was obtained for each flow rate by the relation between error of measurement and time of use (simple linear regression). According to the results, the majority of the equipment presents increasing under-registration errors over time, more pronounced at low flow rates and with less favorable operating conditions. The metrological operation period for flow rates of 30, 120, 750 and 1,500 L h-1 is estimated at approximately 3, 8, 14 and 13 years. This operation period combined with consumption patterns of users will establish the best time to replace the meters.

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