scholarly journals High-Speed Discrimination and Sorting of Submicron Particles Using a Microfluidic Device

Nano Letters ◽  
2014 ◽  
Vol 15 (1) ◽  
pp. 469-475 ◽  
Author(s):  
Sukumar Rajauria ◽  
Christopher Axline ◽  
Claudia Gottstein ◽  
Andrew N. Cleland
Author(s):  
Renqiang Xiong ◽  
Jacob N. Chung

In this paper we used high speed recording to characterize segmented micro-scale air bubble generation in a T-junction and bubble transport in a serpentine micro-channel fabricated in a standard silicon wafer.


2016 ◽  
Vol 10 (1) ◽  
pp. 011912 ◽  
Author(s):  
Pengfei Song ◽  
Xianke Dong ◽  
Xinyu Liu

2020 ◽  
Vol 17 (3) ◽  
pp. 51-59
Author(s):  
Michael Ornstead ◽  
Ruth Hunter ◽  
Mason Valentine ◽  
Cameron Cooper ◽  
Stephen Smith ◽  
...  

A microfluidic device was created and used to demonstrate that supported lipid bilayers can be deposited on clean glass slides and removed using high velocity buffer flow (1-4 m/s linear velocity). This was accomplished by forcing the flow through a microfluidic channel covering an annealed glass coverslip bearing a supported lipid bilayer (SLB). The removal of bilayer material was monitored via fluorescence microscopy, and two basic regimes were observed: at 1-2 m/s smaller areas were stripped, while at 3-4 m/s larger areas were stripped. SLB removal was verified by two means. First, lipid vesicles labeled with a different fluorescent dye were added to the device and filled in holes left by the removal of the original SLB, allowing stripping to be verified visually. Second, the solutions obtained from stripping were concentrated and the fluorescence in the concentrates was measured. The ability to strip SLB from glass provides a relatively gentle method of creating spatially inhomogeneous SLB, which could be a useful tool in the continued investigation of membrane properties and components. KEYWORDS: Supported Lipid Bilayer; Membrane Vesicle; Microfluidic Device


Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 709 ◽  
Author(s):  
Chul Min Kim ◽  
Gyu Man Kim

We present a 512-microchannel geometrical passive breakup device for the mass production of microdroplets. The mass production is achieved through the passive breakup of a droplet into two droplets. The microchannel geometry in the microfluidic device was designed and optimized by focusing on stable droplet splitting for microdroplet preparation and minimizing the hydraulic resistance of the microchannel for achieving high throughput; the minimization of hydraulic resistance was achieved by employing analytical approaches. A total of 512 microdroplets could be prepared from a single liquid plug by making the liquid plug pass through nine sequential T-junctions in the microfluidic device, which led to the splitting of droplets. The microfluidic device was fabricated using conventional photolithography and polydimethylsiloxane (PDMS) casting. We estimated the performance of the microfluidic device in terms of the size distribution and production rate of microdroplets. Microdroplets with a diameter of 40.0 ± 2.2 µm were prepared with a narrow size distribution (coefficient of variation (CV) < 5.5%) for flow rates of disperse (Qd) and continuous phase (Qc) of 2 and 3 mL/h, respectively. Microdroplet production rates were measured using a high-speed camera. Furthermore, monodisperse microdroplets were prepared at 42.7 kHz for Qd and Qc of 7 and 15 mL/h, respectively. Finally, the feasibility of the fabricated microfluidic device was verified by using it to prepare biodegradable chitosan microspheres.


2018 ◽  
Author(s):  
Luis Eudave Ramos

Numerous daily tasks, including car driving, require fine visuospatial tuning. Onesuch visuospatial ability, speed discrimination, declines with aging but its neuralunderpinnings remain unknown. In this study, we use fMRI to explore the effect ofaging during a high speed discrimination task, along with a completeneuropsychological assessment and a simulated driving evaluation in order toexamine how they interact with each other. Beyond confirming that high speeddiscrimination performance is dimished in the elderly, we found that this deficit mightbe partly due to a lack of modulation in the activity and connectivity of the defaultmode network (DMN) in this age group, as well as an over-recruitment of frontal,basal ganglia and cerebellar regions, possibly as a compensatory mecanism. Thisneural pattern could also be translated to our participants’ cognitive and drivingsimulator performance, such that in young adults, a proper DMN modulationcorrelated with better neuropsychological scores and a driving profile, an effect thatseems to be lost in the elderly. These findings contribute to highlight the role of thedefault mode network on visuospatial tasks, how it is age-related and its impact on cognitive functioning and driving performance in a simulator.


2021 ◽  
Vol 4 (1) ◽  
pp. 37
Author(s):  
Inês Maia Gonçalves ◽  
Miguel Madureira ◽  
Inês Miranda ◽  
Helmut Schütte ◽  
Ana Moita ◽  
...  

The diagnosis of several diseases can be performed by analyzing the blood plasma of a patient. Despite extensive research work, there is still a need to improve current low-cost fabrication techniques and devices for the separation of plasma from blood cells. Microfluidic biomedical devices have great potential for that process. Hence, a microfluidic device made by micromilling and sealed with an oxygen plasma technique was tested by means of two different blood analogue fluids. The device has four microchannels with similar geometries but different channel depths. A high-speed video microscopy system was used for the visualization and acquisition of the flow of the analogue fluids throughout the microchannels of the device. Then, the separation of particles and plasma was evaluated with the ImageJ software by measuring and comparing the grey values at the entrance and the exit of the channel. The device showed a significant reduction of the amount of cells between the entrance and the exit of the microchannels. The depth of the channels and the size of the particles were not found to exert any major influence on the separation process. However, it was found that the flow rate affected the separation results, as the best results were obtained for a flow rate of 100 μL/min. Though these results are promising, further analyses and optimizations of microfluidic devices, as well as comparisons between devices sealed using different methods such as the solvent bonding technique, will be conducted in future works.


Author(s):  
E.D. Wolf

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.


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