scholarly journals PDMS Bonding Technologies for Microfluidic Applications: A Review

Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 292
Author(s):  
Alexandra Borók ◽  
Kristóf Laboda ◽  
Attila Bonyár
Keyword(s):  
Oxygen Plasma ◽  
Shear Test ◽  
Peel Test ◽  
Strength Testing ◽  
Surface Activation ◽  
Polyethylene Naphthalate ◽  
Testing Methods ◽  
Advantages And Disadvantages ◽  
Leakage Test ◽  
Bond Strengths

This review summarizes and compares the available surface treatment and bonding techniques (e.g., corona triggered surface activation, oxygen plasma surface activation, chemical gluing, and mixed techniques) and quality/bond-strength testing methods (e.g., pulling test, shear test, peel test, leakage test) for bonding PDMS (polydimethylsiloxane) with other materials, such as PDMS, glass, silicon, PET (polyethylene terephthalate), PI (polyimide), PMMA (poly(methyl methacrylate)), PVC (polyvinyl chloride), PC (polycarbonate), COC (cyclic olefin copolymer), PS (polystyrene) and PEN (polyethylene naphthalate). The optimized process parameters for the best achievable bond strengths are collected for each substrate, and the advantages and disadvantages of each method are discussed in detail.

Genotypic Methods for HIV Drug Resistance Monitoring: The Opportunities and Challenges Faced by China

2019 ◽  
Vol 17 (4) ◽  
pp. 225-239 ◽  
Author(s):  
Lulu Zuo ◽  
Ke Peng ◽  
Yihong Hu ◽  
Qinggang Xu
Keyword(s):  
Drug Resistance ◽  
Virological Suppression ◽  
Testing Methods ◽  
Hiv Drug Resistance ◽  
Advantages And Disadvantages ◽  
Hiv Epidemic ◽  
Routine Surveillance ◽  
The World ◽  
Global Project ◽  
Hiv 1

AIDS is a globalized infectious disease. In 2014, UNAIDS launched a global project of “90-90-90” to end the HIV epidemic by 2030. The second and third 90 require 90% of HIV-1 infected individuals receiving antiretroviral therapy (ART) and durable virological suppression. However, wide use of ART will greatly increase the emergence and spreading of HIV drug resistance and current HIV drug resistance test (DRT) assays in China are seriously lagging behind, hindering to achieve virological suppression. Therefore, recommending an appropriate HIV DRT method is critical for HIV routine surveillance and prevention in China. In this review, we summarized the current existing HIV drug resistance genotypic testing methods around the world and discussed the advantages and disadvantages of these methods.

scholarly journals An Assessment of Surface Treatments for Adhesion of Polyimide Thin Films

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1955
Author(s):  
Marco Cen-Puc ◽  
Andreas Schander ◽  
Minerva G. Vargas Gleason ◽  
Walter Lang
Keyword(s):  
Flexible Electronics ◽  
Oxygen Plasma ◽  
Reactive Ion Etching ◽  
Peel Test ◽  
Scratch Test ◽  
Peel Strength ◽  
Surface Treatments ◽  
Oxygen Plasma Treatment ◽  
Polyimide Films ◽  
Ion Etching

Polyimide films are currently of great interest for the development of flexible electronics and sensors. In order to ensure a proper integration with other materials and PI itself, some sort of surface modification is required. In this work, microwave oxygen plasma, reactive ion etching oxygen plasma, combination of KOH and HCl solutions, and polyethylenimine solution were used as surface treatments of PI films. Treatments were compared to find the best method to promote the adhesion between two polyimide films. The first selection of the treatment conditions for each method was based on changes in the contact angle with deionized water. Afterward, further qualitative (scratch test) and a quantitative adhesion assessment (peel test) were performed. Both scratch test and peel strength indicated that oxygen plasma treatment using reactive ion etching equipment is the most promising approach for promoting the adhesion between polyimide films.

Small specimen techniques for estimation of tensile, fatigue, fracture and crack propagation material model parameters

2021 ◽  
pp. 030932472110252
Author(s):  
Julija Kazakeviciute ◽  
James Paul Rouse ◽  
Davide Focatiis ◽  
Christopher Hyde
Keyword(s):  
Fatigue Fracture ◽  
Structural Integrity ◽  
Standard Specimen ◽  
Creep Behaviour ◽  
Parameter Determination ◽  
Model Parameters ◽  
Small Specimen ◽  
Testing Methods ◽  
Advantages And Disadvantages ◽  
Tensile Fatigue

Small specimen mechanical testing is an exciting and rapidly developing field in which fundamental deformation behaviours can be observed from experiments performed on comparatively small amounts of material. These methods are particularly useful when there is limited source material to facilitate a sufficient number of standard specimen tests, if any at all. Such situations include the development of new materials or when performing routine maintenance/inspection studies of in-service components, requiring that material conditions are updated with service exposure. The potentially more challenging loading conditions and complex stress states experienced by small specimens, in comparison with standard specimen geometries, has led to a tendency for these methods to be used in ranking studies rather than for fundamental material parameter determination. Classifying a specimen as ‘small’ can be subjective, and in the present work the focus is to review testing methods that utilise specimens with characteristic dimensions of less than 50 mm. By doing this, observations made here will be relevant to industrial service monitoring problems, wherein small samples of material are extracted and tested from operational components in such a way that structural integrity is not compromised. Whilst recently the majority of small specimen test techniques development have focused on the determination of creep behaviour/properties as well as sub-size tensile testing, attention is given here to small specimen testing methods for determining specific tensile, fatigue, fracture and crack growth properties. These areas are currently underrepresented in published reviews. The suitability of specimens and methods is discussed here, along with associated advantages and disadvantages.

scholarly journals Quantitative peel test for thin films/layers based on a coupled parametric and statistical study

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Maysam Rezaee ◽  
Li-Chih Tsai ◽  
Muhammad Istiaque Haider ◽  
Armin Yazdi ◽  
Ehsan Sanatizadeh ◽  
...  
Keyword(s):  
Thin Films ◽  
Statistical Study ◽  
Peel Test ◽  
Testing Methods ◽  
Adhesion Properties ◽  
Register Variation ◽  
Quantitative Measurements ◽  
Test Methodology ◽  
Quantitative Results ◽  
Resultant Forces

AbstractThe adhesion strength of thin films is critical to the durability of micro and nanofabricated devices. However, current testing methods are imprecise and do not produce quantitative results necessary for design specifications. The most common testing methods involve the manual application and removal of unspecified tape. This overcome many of the challenges of connecting to thin films to test their adhesion properties but different tapes, variation in manual application, and poorly controlled removal of tape can result in wide variation in resultant forces. Furthermore, the most common tests result in a qualitative ranking of film survival, not a measurement with scientific units. This paper presents a study into application and peeling parameters that can cause variation in the peeling force generated by tapes. The results of this study were then used to design a test methodology that would control the key parameters and produced repeatable quantitative measurements. Testing using the resulting method showed significant improvement over more standard methods, producing measured results with reduced variation. The new method was tested on peeling a layer of paint from a PTFE backing and was found to be sensitive enough to register variation in force due to differing peeling mechanisms within a single test.

Ultrasonic Testing in 25 Minutes

2003 ◽  
Author(s):  
William E. Blum ◽  
Thomas Gryba¨ck
Keyword(s):  
Power Generation ◽  
Quality Control ◽  
Nondestructive Testing ◽  
Ultrasonic Testing ◽  
Basic Theory ◽  
Testing Methods ◽  
Advantages And Disadvantages ◽  
Basic Understanding ◽  
Fundamental Understanding ◽  
Nondestructive Testing Methods

Nondestructive Testing (AKA NDT, NDI, NDE) is an integral part of any power generation program. Ultrasonic Testing (UT) is one NDT method used to determine the integrity of materials and components. Managers, engineers, quality control personnel and others often require a fundamental understanding of the nondestructive testing methods used in their operations. This paper introduces basic theory, advantages and disadvantages, typical equipment and applications of ultrasonic testing. It is designed to give the reader a basic understanding of ultrasonic testing.

scholarly journals UV/Ozone Surface Treatment for Bonding of Elastomeric COC-Based Microfluidic Devices

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 943
Author(s):  
Eva Gleichweit ◽  
Christian Baumgartner ◽  
Reinhard Diethardt ◽  
Alexander Murer ◽  
Werner Sallegger ◽  
...  
Keyword(s):  
Microfluidic Devices ◽  
Thermoplastic Elastomer ◽  
Bonding Process ◽  
Test Method ◽  
Polymer Materials ◽  
Surface Activation ◽  
Molded Parts ◽  
Injection Molded ◽  
Bond Strengths ◽  
Uv Ozone

Reliable bonding of microstructured polymer parts is one of the major challenges in industrial fabrication of microfluidic devices. In the present work, the effects of a UV/ozone surface activation on the bonding process were investigated for the combination of a commonly used thermoplastic cyclic olefin copolymer (COC) with an elastomeric COC (eCOC) as a new thermoplastic elastomer material. Bonding was studied using two-component injection molded parts of COC and eCOC, together with microfluidic COC chips. Surface activation and bonding process parameters were optimized and bond strengths were characterized by the wedge test method. The results showed that strong bonding of this polymer materials combination can be achieved at temperatures significantly below the bulk glass transition temperature of COC.

Diagnostics of aviation equipment. Methods and means of non-destructive testing of the technical condition of the aircraft

2017 ◽  
Author(s):  
Мартыненко ◽  
Elena Martynenko
Keyword(s):  
Physical Nature ◽  
Optical Devices ◽  
Civil Aviation ◽  
Measuring Instruments ◽  
Non Destructive Testing ◽  
Testing Methods ◽  
Destructive Testing ◽  
Ray Method ◽  
Advantages And Disadvantages ◽  
Non Destructive

This manual contains information about the appointment and the physical nature of the application existing non-destructive testing methods, their advantages and disadvantages. The manual contains a brief historical information about the development of non-destructive testing methods in manufacturing aircraft devices, the classification and possible causes of occurrence of various defects on which the studied method of non-destructive testing are directed. The first part of the manual, of the main methods that are used to detect the defects in any instrument control. The detailed classification of measuring instruments and optical devices are given. Moreover, the construction and the ways (the principles) of work of complex measuring instruments and optical devices, including endoscopes are given. The current devices and systems for visual inspection of fiber-hidden objects and internal cavities are considered. More detailed consideration in the manual is given to the capillary, magnetic, acoustic, eddy current non-destructive testing methods and techniques of radiographic(X-ray and gamma-ray method). Particular attention is paid to the field of practical application of different methods. A lot of attention is given to modern means of non-destructive testing of domestic and foreign production. The manual contains a significant amount of drawings and diagrams, which allows to increase the visibility and the accessibility of presentation. It is drawn up with the interdisciplinary course program MDK 01.01.03 "Technical maintenance of aircraft and engines" and is intended for students of the above mentioned specialization 25.02.01 branches of secondary vocational education. The manual can also be used by the students of the training courses for engineering and technical personnel of the enterprises of civil aviation.

scholarly journals New test method with a Hybrid III Anthropomorphic Dummy for Textile Safety Harnesses

2020 ◽  
Vol 28 (1(139)) ◽  
pp. 81-86
Author(s):  
Krzysztof Baszczyński
Keyword(s):  
Test Method ◽  
Strength Testing ◽  
Head Acceleration ◽  
Testing Methods ◽  
Testing Method ◽  
Experimental Stand ◽  
Hybrid Iii ◽  
Mechanical Factors ◽  
Fall Arrest ◽  
Full Body

A full body harness is a basic component of personal fall arrest equipment. It is made from webbing connected by seams and metal fittings to firmly hold and support the user’s body. The paper proposes a new method for full body harness testing using a Hybrid III anthropomorphic dummy; also the design of the experimental stand and software used are described. The method analyses the behaviour of a dummy during a fall arrest under well-defined conditions. The critical mechanical factors measured during the study presented were: the head acceleration, forces acting on the spine, the position of the dummy, the impacts of harness elements to the head, etc. The tests identified some potentially dangerous phenomena associated with falls from a height. The harness testing method developed turned out to be a valuable tool that should be applied in conjunction with existing strength testing methods.

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