Fabricating Plastic Microfluidic Devices With Photodefinable Microvalves for Protein Separations

2005 ◽  
Author(s):  
Carl K. Fredrickson ◽  
Champak Das ◽  
Fernando T. Tavares ◽  
Ryan Ferguson ◽  
Zheng Xia ◽  
...  
Keyword(s):  
Protein Separation ◽  
Raw Materials ◽  
Low Cost ◽  
Microfluidic Devices ◽  
Hydraulic Press ◽  
Protein Separations ◽  
In Situ Gel ◽  
Separation Media ◽  
Bio Compatibility

This paper describes the results of fabricating plastic microfluidic devices and creating a microvalve array for protein separation. Plastic devices are selected due to low cost of raw materials, bio-compatibility, and disposability. Although the methods for fabricating plastic devices have appeared in literature, reports typically indicate one set of conditions that yield functional devices. We report a systematic study of fabrication process parameters including compression rate, molding temperature, and the compression force used by a hydraulic press. Their effects on the device thickness, channel dimension, and pattern transfer fidelity will be discussed. In addition, we investigated creating an array of pseudo-microvalves using photodefinable, in situ gel polymerization. The valves were developed for introducing two types of separation media for performing two-dimensional protein separation in a microfluidic device. We also demonstrated rapid protein separation using the mechanism for the first dimension, isoelectric focusing.

Microfluidic Valve Arrays in Thermoplastic Devices

2012 ◽  
Author(s):  
Z. Hugh Fan ◽  
Pan Gu ◽  
Shancy Augustine ◽  
Ke Liu ◽  
Harvy Freitag ◽  
...  
Keyword(s):  
Protein Separation ◽  
Low Cost ◽  
Building Blocks ◽  
Elastic Membrane ◽  
Two Dimensional ◽  
Thermal Actuation ◽  
Thermally Actuated ◽  
Separation Media ◽  
Orthogonal Channels ◽  
Cyclic Olefin Copolymers

Thermoplastics have been increasingly employed for microfluidic devices due to their manufacturability, low cost, and biocompatibility. A microfluidic device consists of a number of necessary building blocks, including microvalves that are often used for flow regulation. The state-of-the-art of the microfluidic valve technology is polydimethylsiloxane (PDMS)-based elastic membrane valve. This paper is to report the integration of the elastomer valve into a thermoplastic device. The valves were designed for a two-dimensional protein separation device, which was fabricated from cyclic olefin copolymers (COC). To realize the goal of integrating the elastomer-based valves in the device, the key challenge is to achieve strong bonding between COC and PDMS so that the device will not delaminate when a pressure is built up after the valves are closed. Microvalve arrays were fabricated in a COC/PDMS/COC device to facilitate the introduction of two types of separation media, without cross-contamination, into orthogonal channels in order to achieve two-dimensional separation. In addition, we studied thermal actuation in the microvalve, as an alternative to pneumatic actuation in the conventional PDMS-based elastomer valve. The thermally actuated valves can be self-contained, requiring less-bulky external accessories than pneumatically actuated valves.

scholarly journals FeS2/C Nanowires as an Effective Catalyst for Oxygen Evolution Reaction by Electrolytic Water Splitting

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3364 ◽  
Author(s):  
Kefeng Pan ◽  
Yingying Zhai ◽  
Jiawei Zhang ◽  
Kai Yu
Keyword(s):  
Water Splitting ◽  
Rational Design ◽  
Raw Materials ◽  
Low Cost ◽  
Clean Energy ◽  
Electrochemical Activation ◽  
Practical Applications ◽  
Current Densities ◽  
To Receive

Electrolytic water splitting with evolution of both hydrogen (HER) and oxygen (OER) is an attractive way to produce clean energy hydrogen. It is critical to explore effective, but low-cost electrocatalysts for the evolution of oxygen (OER) owing to its sluggish kinetics for practical applications. Fe-based catalysts have advantages over Ni- and Co-based materials because of low costs, abundance of raw materials, and environmental issues. However, their inefficiency as OER catalysts has caused them to receive little attention. Herein, the FeS2/C catalyst with porous nanostructure was synthesized with rational design via the in situ electrochemical activation method, which serves as a good catalytic reaction in the OER process. The FeS2/C catalyst delivers overpotential values of only 291 mV and 338 mV current densities of 10 mA/cm2 and 50 mA/cm2, respectively, after electrochemical activation, and exhibits staying power for 15 h.

scholarly journals Synthesis of nearly spherical AlN particles by an in-situ nitriding combustion route

2021 ◽  
Vol 10 (2) ◽  
pp. 291-300
Author(s):  
Zhilei Wei ◽  
Kang Li ◽  
Bangzhi Ge ◽  
Chaowei Guo ◽  
Hongyan Xia ◽  
...  
Keyword(s):  
Particle Size ◽  
Combustion Temperature ◽  
High Efficiency ◽  
Raw Materials ◽  
Low Cost ◽  
Synthesis Method ◽  
Preparation Methods ◽  
Average Size ◽  
Micrometer Size

AbstractSpherical AlN powders with micrometer size have attracted great attention owing to their good fluidity and dispersity. However, the industrial preparation methods usually require high temperature and long soaking time, which lead to the high cost and limit the wide application of the products. Herein, nearly spherical AlN particles with the average size of 2.5 µm were successfully synthesized via an in-situ combustion synthesis method. The effect of N2 pressure, NH4Cl content, and Al particle size on the combustion reaction procedure, phase composition, and microstructure of the products was systematically investigated. The results showed that the decreased N2 pressure, increased NH4Cl content, and Al particle size led to the decreasing of combustion temperature and speed, which further affected the morphology of the products. As a result, low N2 pressure (0.2 MPa), a small amount of NH4Cl (0.5 wt%), and fine Al particles (∼2.5 µm) contributed to a moderate combustion temperature and facilitated the formation of nearly spherical AlN particles. In addition, based on the gas-releasing assisted quenching experiments and thermo-kinetic analysis, a two-step growth mechanism for the nearly spherical AlN particles was rationally proposed. The present method shows the advantages of low cost and high efficiency for preparing nearly spherical AlN particles, which can be used as raw materials for electronic substrates and fillers for packaging materials.

Diamond as a wear-resistant coating

1993 ◽  
Vol 342 (1664) ◽  
pp. 297-311 ◽  
Keyword(s):  
Raw Materials ◽  
Low Cost ◽  
Chemical Vapour ◽  
Polycrystalline Diamond ◽  
Low Pressure ◽  
Hard Metal ◽  
Composite Powders ◽  
Cvd Diamond Coating ◽  
Metal Tools

Refractory chemical vapour deposition (CVD) coatings strongly improve the performances of hard metal tools. Low-pressure diamond synthesis permits both in situ CVD diamond coating and freestanding low-pressure diamond sheet fabrication. The performance of coated and freestanding bonded diamond layer tools approaches those of commercial polycrystalline diamond (PCD) products. Low-pressure diamond grits and new composite powders could provide new and extraordinary grinding powders of raw materials for novel types of PCD composites. Commercial production is now mainly a scaling-up problem. Reliable and low-cost fabrications are among the most important requirements. As these applications tolerate the use of poly crystalline layers, they are likely to be between those industrial low-pressure diamond products having soon a significant market share.

scholarly journals Regenerasi In-Situ Adsorben Karbon Aktif Tipe Granul dengan Metode Termal

2019 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Yanti Suprianti ◽  
Annisa Syafitri Kurniasetyawati
Keyword(s):  
Activated Carbon ◽  
Raw Materials ◽  
Linear Trend ◽  
Low Cost ◽  
Carbon Adsorbent ◽  
Thermal Method ◽  
Adsorption Of Co2 ◽  
Carbon Dioxide Co2 ◽  
Adsorption Desorption

Produk biogas memiliki spesifikasi yang masih perlu ditingkatkan (mengandung metana, CH4 50-70%, dan karbon dioksida, CO2 30 – 49%), agar dapat bersaing dengan gas alam, yaitu lebih dari 98% metana. Metode pemurnian melalui adsorpsi CO2 paling banyak diterapkan, karena tidak memerlukan biaya tinggi, jika dibandingkan teknologi pemisahan konvensional lain. Tetapi, media adsorben karbon aktif akan mengalami kejenuhan dalam waktu tertentu. Salah satu metode yang dapat digunakan untuk meregenerasi karbon aktif yang jenuh oleh CO2 yaitu dengan peningkatan temperatur melalui metoda termal. Pada penelitian ini dilakukan regenerasi in-situ dengan peningkatan temperatur karbon aktif di dalam kolom adsorpsi-desorpsi, dengan alat dapat mengakomodasi tiga pola operasi, yaitu adsorpsi, regenerasi/desorpsi, dan pengosongan gas. Alat terdiri atas kolom yang dilengkapi perpipaaan, blower pendorong udara, heater dan thermostat untuk pemanas dan pengatur temperatur udara. Hasil uji alat menunjukkan bahwa durasi proses adsorpsi hingga mencapai kejenuhan adalah 30 menit pada siklus pertama dan 40 menit pada siklus kedua. Selanjutnya, durasi proses desorpsi dari siklus pertama hingga ketiga menunjukkan peningkatan linier, dipengaruhi oleh temperatur udara pemanas, dengan penurunan konsentrasi Ca(OH)2 hingga masih menunjukkan tren peningkatan. Setelah dilakukan tiga siklus proses adsorspi-desorpsi didapatkan bahwa performa dari karbon aktif masih belum mengalami penurunan kapasitas.Biogas have certain specifications that need to be improved (contain methane, CH4, 50-70%, and carbon dioxide, CO2, 30-49%), in order to compete with natural gas ( >98% methane). The adsorption of CO2 is the most widely applied to purify biogas since it considered as low cost, in terms of energy supply and raw materials. However, activated carbon adsorbent will be saturated and must be regenerated. One of the methods that can be used to regenerate CO2-saturated activated carbon is using thermal method. In this research, the in-situ regeneration was carried out by increasing temperature of the activated carbon in adsorption-desorption column, which accommodate three operating patterns, namely adsorption, regeneration/desorption, and gas discharge. The tool consists of columns, piping, blower, heater and thermostat for air heating and controlling temperature. The result showed that the saturation time was 30 minutes and 40 minutes, respectively in 1st and 2nd cycle. The duration of the desorption from the 1st to 3rd cycle showed a linear trend, influenced by heating air temperature. And the reduction in Ca(OH)2 concentration still showed increasing trend after three adsorption-desorption cycles carried out, so the performance or adsorption capacity of activated carbon had not yet been decreased.

scholarly journals Synthesis of nearly spherical AlN particles by an in-situ nitriding combustion route

2020 ◽  
Author(s):  
Zhilei Wei ◽  
Kang Li ◽  
Bangzhi Ge ◽  
Chaowei Guo ◽  
Hongyan Xia ◽  
...  
Keyword(s):  
Particle Size ◽  
Combustion Temperature ◽  
High Efficiency ◽  
Raw Materials ◽  
Low Cost ◽  
Synthesis Method ◽  
Preparation Methods ◽  
Average Size ◽  
Micrometer Size

Abstract Spherical AlN powders with micrometer size have attracted great attention owing to their good fluidity and dispersity. However, the industrial preparation methods usually require high temperature and long soaking time, which lead to the high cost and limit the wide application of the products. Herein, nearly spherical AlN particles with the average size of 2.5 μm were successfully synthesized via an in-situ combustion synthesis method. The effect of N 2 pressure, NH 4 Cl content and Al particle size on the combustion reaction procedure, phase composition and microstructure of the products was systematically investigated. The results showed that the decreased N 2 pressure, increased NH 4 Cl content and Al particle size led to the decreasing of combustion temperature and speed, which further affected the morphology of the products. As a result, low N 2 pressure (0.2 MPa), a small amount of NH 4 Cl (0.5 wt%) and fine Al particles (~2.5 μm) contributed to a moderate combustion temperature and facilitated the formation of nearly spherical AlN particles. In addition, based on the gas-releasing assisted quenching experiments and thermo-kinetic analysis, a two-step growth mechanism for the nearly spherical AlN particles was rationally proposed. The present method shows the advantages of low cost and high efficiency for preparing nearly spherical AlN particles, which can be used as raw materials for electronic substrates and fillers for packaging materials.

scholarly journals Synthesis of nearly spherical AlN particles by an in-situ nitriding combustion route

2020 ◽  
Author(s):  
Zhilei Wei ◽  
Kang Li ◽  
Bangzhi Ge ◽  
Chaowei Guo ◽  
Hongyan Xia ◽  
...  
Keyword(s):  
Particle Size ◽  
Combustion Temperature ◽  
High Efficiency ◽  
Raw Materials ◽  
Low Cost ◽  
Synthesis Method ◽  
Preparation Methods ◽  
Average Size ◽  
Micrometer Size

Abstract Spherical AlN powders with micrometer size have attracted great attention owing to their good fluidity and dispersity. However, the industrial preparation methods usually require high temperature and long soaking time, which lead to the high cost and limit the wide application of the products. Herein, nearly spherical AlN particles with the average size of 2.5 µm were successfully synthesized via an in-situ combustion synthesis method. The effect of N2 pressure, NH4Cl content and Al particle size on the combustion reaction procedure, phase composition and microstructure of the products was systematically investigated. The results showed that the decreased N2 pressure, increased NH4Cl content and Al particle size led to the decreasing of combustion temperature and speed, which further affected the morphology of the products. As a result, low N2 pressure (0.2 MPa), a small amount of NH4Cl (0.5 wt%) and fine Al particles (~ 2.5 µm) contributed to a moderate combustion temperature and facilitated the formation of nearly spherical AlN particles. In addition, based on the gas-releasing assisted quenching experiments and thermo-kinetic analysis, a two-step growth mechanism for the nearly spherical AlN particles was rationally proposed. The present method shows the advantages of low cost and high efficiency for preparing nearly spherical AlN particles, which can be used as raw materials for electronic substrates and fillers for packaging materials.

scholarly journals Systematic Review: Microfluidics and Plasmodium

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1245
Author(s):  
Nicolas Thorne ◽  
Luis Flores-Olazo ◽  
Rocío Egoávil-Espejo ◽  
Emir A. Vela ◽  
Julien Noel ◽  
...  
Keyword(s):  
Systematic Review ◽  
Low Cost ◽  
Severe Disease ◽  
Microfluidic Devices ◽  
Diagnostic Methods ◽  
Remote Locations ◽  
The Past ◽  
New Directions ◽  
Primary Focus

Malaria affects 228 million people worldwide each year, causing severe disease and worsening the conditions of already vulnerable populations. In this review, we explore how malaria has been detected in the past and how it can be detected in the future. Our primary focus is on finding new directions for low-cost diagnostic methods that unspecialized personnel can apply in situ. Through this review, we show that microfluidic devices can help pre-concentrate samples of blood infected with malaria to facilitate the diagnosis. Importantly, these devices can be made cheaply and be readily deployed in remote locations.

To Eliminate Curtain Effect of FIB TEM Samples by a Combination of Sample Dicing and Backside Milling

2014 ◽  
Author(s):  
Jian-Shing Luo ◽  
Hsiu Ting Lee
Keyword(s):  
Sample Preparation ◽  
Focused Ion Beam ◽  
Preparation Method ◽  
Low Cost ◽  
Ion Beam ◽  
Sample Preparation Method ◽  
Site Specific ◽  
Dual Beam ◽  
Transmission Electron

Abstract Several methods are used to invert samples 180 deg in a dual beam focused ion beam (FIB) system for backside milling by a specific in-situ lift out system or stages. However, most of those methods occupied too much time on FIB systems or requires a specific in-situ lift out system. This paper provides a novel transmission electron microscopy (TEM) sample preparation method to eliminate the curtain effect completely by a combination of backside milling and sample dicing with low cost and less FIB time. The procedures of the TEM pre-thinned sample preparation method using a combination of sample dicing and backside milling are described step by step. From the analysis results, the method has applied successfully to eliminate the curtain effect of dual beam FIB TEM samples for both random and site specific addresses.

Sign in / Sign up

Export Citation Format

Share Document