scholarly journals Easily fabricated monolithic fluoropolymer chips for sensitive long-term absorbance measurement in droplet microfluidics

RSC Advances ◽  
2020 ◽  
Vol 10 (51) ◽  
pp. 30975-30981
Author(s):  
Adrian M. Nightingale ◽  
Sammer-ul Hassan ◽  
Kyriacos Makris ◽  
Wahida T. Bhuiyan ◽  
Terry J. Harvey ◽  
...  
Keyword(s):  
Droplet Microfluidics ◽  
Microfluidic Chips ◽  
Absorbance Measurement ◽  
Accessible Method

We present a widely accessible method for fabricating monolithic fluoropolymer microfluidic chips, which allows droplet absorbance measurement over multi-month periods.

scholarly journals Facile Use of ZnO Nanopowders to Protect Old Manual Paper Documents

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5452
Author(s):  
Ludmila Motelica ◽  
Aurelian Popescu ◽  
Anca-Gabriela Răzvan ◽  
Ovidiu Oprea ◽  
Roxana-Doina Truşcă ◽  
...  
Keyword(s):  
Hand Hygiene ◽  
Antimicrobial Agents ◽  
Storage Conditions ◽  
Human Pathogens ◽  
Accessible Method

One of the main problems faced by libraries, archives and collectors is the mold degradation of the paper-based documents, books, artworks etc. Microfungi (molds) emerge in regular storage conditions of such items (humidity, usually over 50%, and temperatures under 21 °C). If the removal of the visible mycelium is relatively easy, there is always the problem of the subsequent appearance of mold as the spores remain trapped in the cellulosic, fibrillary texture, which acts as a net. Moreover, due to improper hand hygiene bacteria contamination, old books could represent a source of biohazard, being colonized with human pathogens. An easy and accessible method of decontamination, which could offer long term protection is therefore needed. Here, we present a facile use of the ZnO nanopowders as antimicrobial agents, suitable for cellulose-based products, conferring an extended antibacterial and anti-microfungal effect. The proposed method does not adversely impact on the quality of the cellulose documents and could be efficiently used for biodegradation protection.

Production of Fluoropolymer Microchips for Droplet Microfluidics and DNA Amplification

2010 ◽  
Author(s):  
Stefano Begolo ◽  
Guillaume Colas ◽  
Laurent Malaquin ◽  
Jean-Louis Viovy
Keyword(s):  
Low Temperatures ◽  
Dna Amplification ◽  
Droplet Microfluidics ◽  
Cross Contamination ◽  
Uniform Pressure ◽  
Microfluidic Chips ◽  
Fabrication Technique ◽  
Flexible Membrane ◽  
Low Surface Energy ◽  
Solvent Bonding

In this paper we present a novel fabrication technique for production of monolithic microfluidic chips made from a fluoropolymer (Dyneon THV). This material retains numerous properties of commonly used fluoropolymers (low surface energy and compatibility with chemicals such as organic solvents or fluorinated oil), and is easily processable at relatively low temperatures (lower than 180°C). We used hot embossing to mold microstructures on flat sheets of this polymer. The microchips are sealed through a combination of thermal and solvent bonding by applying uniform pressure with a flexible membrane. These closed channels can be used for the production and circulation of aqueous droplets in fluorinated oil. This droplet microfluidic configuration is suitable for DNA amplification since it avoids cross contamination between adjacent droplets.

scholarly journals Long-term hydrophilization of polydimethylsiloxane (PDMS) for capillary filling microfluidic chips

2019 ◽  
Vol 24 (1) ◽  
Author(s):  
Farzin Jahangiri ◽  
Tuuli Hakala ◽  
Ville Jokinen
Keyword(s):  
Cold Storage ◽  
Storage Temperature ◽  
Microfluidic Channel ◽  
Vibration Band ◽  
Microfluidic Chips ◽  
Thermally Activated ◽  
Capillary Filling ◽  
Different Temperatures ◽  
Long Term Preservation

AbstractWe present a simple and facile method for long-term preservation of hydrophilicity of oxygen plasma-hydrophilized poly (dimethylsiloxane) (PDMS) by cold storage. We show that storage under temperature of − 80 °C can maintain superhydrophilicity of plasma-exposed PDMS for at least 100 days. Storage at − 15 °C and at 22 °C room temperature (RT) is shown to exhibit, respectively, about half and full recovery of the original hydrophobicity after 100 days in storage. Furthermore, we investigated the implications of the cold storage for microfluidic applications, the capillary filling rate and the ability of the flow to bypass geometrical obstacles in a microfluidic channel. It is shown that the preservation of capillary filling properties of microchannels is in close agreement with the contact angle (CA) measurements and that the colder the storage temperature, the better the capillary filling capability of the channels is preserved. We ascribe the significantly reduced recovery rate to reduced thermally activated relaxation phenomena such as diminished diffusion of low molecular weight species (LMW) in the polymer matrix at colder temperatures. This is supported by ATR-FTIR measurements of the OH vibration band over time for samples stored at different temperatures.

scholarly journals In Situ Fine‐Tuning of Microfluidic Chips by Swelling and Its Application to Droplet Microfluidics

2019 ◽  
Vol 4 (8) ◽  
pp. 1900232
Author(s):  
Juan H. González‐Estefan ◽  
Mathieu Gonidec ◽  
Thi Thiet Vu ◽  
Nathalie Daro ◽  
Guillaume Chastanet
Keyword(s):  
Droplet Microfluidics ◽  
Fine Tuning ◽  
Microfluidic Chips

scholarly journals Automated Platform for Long-Term Culture and High-Content Phenotyping of Single C. elegans Worms

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
H. B. Atakan ◽  
R. Xiang ◽  
M. Cornaglia ◽  
L. Mouchiroud ◽  
E. Katsyuba ◽  
...  
Keyword(s):  
High Throughput ◽  
Agar Plate ◽  
Model Organism ◽  
Suitable Model ◽  
Microfluidic Chips ◽  
Long Term Culture ◽  
C Elegans ◽  
Bleaching Procedure ◽  
Automated Platform

Abstract The nematode Caenorhabditis elegans is a suitable model organism in drug screening. Traditionally worms are grown on agar plates, posing many challenges for long-term culture and phenotyping of animals under identical conditions. Microfluidics allows for ‘personalized’ phenotyping, as microfluidic chips permit collecting individual responses over worms’ full life. Here, we present a multiplexed, high-throughput, high-resolution microfluidic approach to culture C. elegans from embryo to the adult stage at single animal resolution. We allocated single embryos to growth chambers, for observing the main embryonic and post-embryonic development stages and phenotypes, while exposing worms to up to 8 different well-controlled chemical conditions. Our approach allowed eliminating bacteria aggregation and biofilm formation-related clogging issues, which enabled us performing up to 80 hours of automated single worm culture studies. Our microfluidic platform is linked with an automated phenotyping code that registers organism-associated phenotypes at high-throughput. We validated our platform with a dose-response study of the anthelmintic drug tetramisole by studying its influence through the life cycle of the nematodes. In parallel, we could observe development effects and variations in single embryo and worm viability due to the bleaching procedure that is standardly used for harvesting the embryos from a worm culture agar plate.

scholarly journals Cultivation and characterization of human midbrain organoids in sensor integrated microfluidic chips

2019 ◽  
Author(s):  
Sarah Spitz ◽  
Cristian Zanetti ◽  
Silvia Bolognin ◽  
Mudiwa Nathasia Muwanigwa ◽  
Lisa Smits ◽  
...  
Keyword(s):  
Induced Pluripotent Stem Cell ◽  
Microfluidic Chips ◽  
Interstitial Flow ◽  
Precise Control ◽  
Non Invasive ◽  
Dynamic Cultivation ◽  
Induced Pluripotent

1.ABSTRACTWith its ability to emulate microarchitectures and functional characteristics of native organs in vitro, induced pluripotent stem cell (iPSC) technology has enabled the generation of a plethora of organotypic constructs, including that of the human midbrain. However, reproducibly engineering and differentiating such human midbrain organoids (hMOs) under a biomimetic environment favorable for brain development still remains challenging. This study sets out to address this problem by combining the potential of iPSC technology with the advantages of microfluidics, namely its precise control over fluid flow combined with sensor integration. Here, we present a novel sensor-integrated platform for the long-term cultivation and non-invasive monitoring of hMOs under an interstitial flow regime. Our results show that dynamic cultivation of iPSC-derived hMOs maintains high cellular viabilities and dopaminergic neuron differentiation over prolonged cultivation periods of up to 50 days.

scholarly journals Sequentially addressable dielectrophoretic array for high-throughput sorting of large-volume biological compartments

2020 ◽  
Vol 6 (22) ◽  
pp. eaba6712 ◽  
Author(s):  
A. Isozaki ◽  
Y. Nakagawa ◽  
M. H. Loo ◽  
Y. Shibata ◽  
N. Tanaka ◽  
...  
Keyword(s):  
Single Cell ◽  
High Speed ◽  
Single Cell Analysis ◽  
Droplet Microfluidics ◽  
Cell Analysis ◽  
Green Biotechnology ◽  
Speed Flow ◽  
Droplet Sorting ◽  
On Chip

Droplet microfluidics has become a powerful tool in precision medicine, green biotechnology, and cell therapy for single-cell analysis and selection by virtue of its ability to effectively confine cells. However, there remains a fundamental trade-off between droplet volume and sorting throughput, limiting the advantages of droplet microfluidics to small droplets (<10 pl) that are incompatible with long-term maintenance and growth of most cells. We present a sequentially addressable dielectrophoretic array (SADA) sorter to overcome this problem. The SADA sorter uses an on-chip array of electrodes activated and deactivated in a sequence synchronized to the speed and position of a passing target droplet to deliver an accumulated dielectrophoretic force and gently pull it in the direction of sorting in a high-speed flow. We use it to demonstrate large-droplet sorting with ~20-fold higher throughputs than conventional techniques and apply it to long-term single-cell analysis of Saccharomyces cerevisiae based on their growth rate.

scholarly journals Transitioning from multi-phase to single-phase microfluidics for long-term culture and treatment of multicellular spheroids

Lab on a Chip ◽  
2016 ◽  
Vol 16 (18) ◽  
pp. 3548-3557 ◽  
Author(s):  
Kay S. McMillan ◽  
Marie Boyd ◽  
Michele Zagnoni
Keyword(s):  
Single Phase ◽  
Droplet Microfluidics ◽  
Multicellular Spheroids ◽  
Long Term Culture ◽  
Multi Phase

We present a new microfluidic protocol for spheroid based assays that combines the compartmentalisation properties of droplet microfluidics with controllable perfusion typical of single-phase microfluidics.

scholarly journals OsciDrop: A versatile on-demand droplet generator

2021 ◽  
Author(s):  
Shun Ye ◽  
Xu Zheng ◽  
Caiming Li ◽  
Weihang Huang ◽  
Yi Tao ◽  
...  
Keyword(s):  
African Swine Fever Virus ◽  
African Swine Fever ◽  
Droplet Microfluidics ◽  
Droplet Generation ◽  
Microfluidic Chips ◽  
Droplet Generator ◽  
Dna Templates ◽  
On Demand ◽  
High Uniformity ◽  
Monodisperse Droplets

Droplet microfluidics has become a powerful tool in many biological and clinical applications to high-throughput encapsulate reactions with single-cell and single-molecular resolutions. Microfluidic chips, such as flow-focusing droplet generators, have become commonplace in microfluidic laboratories. However, the expensive and precision-demanding microfabrication hinders their widespread use in many biomedical laboratories and clinical facilities. Herein, we present a versatile chip-free droplet generator, termed as OsciDrop, for on-demand generating size-tunable droplets with high uniformity. OsciDrop segments the fluid flowing out of the orifice of a micropipette tip into droplets by oscillating the tip under the surface of a continuous oil phase. We investigated the factors influencing droplet generation by examining several control parameters. Results show that flow rate, oscillating amplitude, and frequency are key parameters to on-demand generate monodisperse droplets. Flexible, repeatable droplet generation by OsciDrop was successfully achieved. Importantly, using an optimal asymmetrical oscillation waveform, OsciDrop can controllably generate monodisperse droplets spanning a wide volume range (200 pL - 2 μL). To demonstrate the capability of OsciDrop for chip-free droplet assays, a digital loop-mediated isothermal amplification (dLAMP) was performed to absolutely quantify African swine fever virus (ASFV) DNA templates. The OsciDrop method opens up a feasible and versatile avenue to perform droplet-based assays, exhibiting full accessibility for chip-free droplet microfluidics.

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