Fabrication of a Three-Layer PDMS Pneumatic Microfluidic Chip for Micro Liquid Sample Operation

2019 ◽  
Vol 25 (2) ◽  
pp. 151-161 ◽  
Author(s):  
Xuling Liu ◽  
Songjing Li
Keyword(s):  
Surface Properties ◽  
Cross Section ◽  
Liquid Layer ◽  
Oxygen Plasma ◽  
Microfluidic Chips ◽  
Liquid Sample ◽  
Negative Photoresist ◽  
Positive Photoresist ◽  
Control Layer ◽  
Dry Film

The emphasis of this paper lies in the fabrication of a three-layer polydimethylsiloxane chip for micro liquid sample operation. In this paper, the microchannels with a rectangular control layer cross section are fabricated based on a dry-film negative photoresist mold, while the microchannels with a rounded liquid layer cross section are fabricated by a positive photoresist reflow mold. The relationships between temperature and the time of reflow and the arc level of the liquid layer mold are discussed. Different ratios, curing temperatures, and curing times are used to fabricate the two PDMS layers to improve their toughness and plasticity separately. The PDMS slabs with microstructure networks are treated with oxygen plasma to improve their surface properties. The improved surface properties serve to reduce the temperature and time, and improve the sealing strength, which is as effective as adding PDMS in varying ratios. The micro liquid sample operation experiments show that high levels of pinching off and mixing performances on pneumatic microfluidic chips are obtained more easily.

scholarly journals On the Effectiveness of Oxygen Plasma and Alkali Surface Treatments to Modify the Properties of Polylactic Acid Scaffolds

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1643
Author(s):  
Ricardo Donate ◽  
María Elena Alemán-Domínguez ◽  
Mario Monzón
Keyword(s):  
Surface Properties ◽  
Enzymatic Degradation ◽  
Oxygen Plasma ◽  
Physicochemical Characterization ◽  
Surface Treatments ◽  
Carboxyl Groups ◽  
Scanning Calorimetry ◽  
Water Contact ◽  
Angle Measurements ◽  
3D Printed

Surface modification of 3D-printed PLA structures is a major issue in terms of increasing the biofunctionality and expanding the tissue engineering applications of these parts. In this paper, different exposure times were used for low-pressure oxygen plasma applied to PLA 3D-printed scaffolds. Alkali surface treatments were also evaluated, aiming to compare the modifications introduced on the surface properties by each strategy. Surface-treated samples were characterized through the quantification of carboxyl groups, energy-dispersive X-ray spectroscopy, water contact angle measurements, and differential scanning calorimetry analysis. The change in the surface properties was studied over a two-week period. In addition, an enzymatic degradation analysis was carried out to evaluate the effect of the surface treatments on the degradation profile of the 3D structures. The physicochemical characterization results suggest different mechanism pathways for each type of treatment. Alkali-treated scaffolds showed a higher concentration of carboxyl groups on their surface, which enhanced the enzymatic degradation rate, but were also proven to be more aggressive towards 3D-printed structures. In contrast, the application of the plasma treatments led to an increased hydrophilicity of the PLA surface without affecting the bulk properties. However, the changes on the properties were less steady over time.

scholarly journals Electroplating moulds using dry film thick negative photoresist

2003 ◽  
Vol 13 (4) ◽  
pp. S67-S74 ◽  
Author(s):  
E Kukharenka ◽  
M M Farooqui ◽  
L Grigore ◽  
M Kraft ◽  
N Hollinshead
Keyword(s):  
Negative Photoresist ◽  
Dry Film

Simulation Research on Bonded Microchannel Deformation of Polymer Microfluidic Chip

2012 ◽  
Vol 246-247 ◽  
pp. 1204-1208
Author(s):  
Lei Huang ◽  
Zhang Wang ◽  
Chun Peng Chu ◽  
Bing Yan Jiang
Keyword(s):  
Cross Section ◽  
Dimensional Accuracy ◽  
Microfluidic Chips ◽  
Cross Sectional ◽  
Simulation Research ◽  
Software Simulation ◽  
Finite Element Software ◽  
Varied Temperature ◽  
Bonding Method ◽  
Sectional Shape

A new bonding method of microfluidic chips, bonding in-mold, was presented. Finite element software simulation was used to study the deformation of microchannels in poly methyl methacrylate (PMMA) bonded chips. Varied temperature and compression thickness have been taken into account. Results showed that bonded microchannel cannot maintain the cross-sectional shape and dimensional accuracy. The area of cross-section was smaller. Its height changes since the substrate’s raised up and the cover plate’s bulged down. But the width dimension of microchannel was essentially unchanged. The deformation caused by thermal expansion is small. Experimental data show that compressed thickness has a greater impact than temperature.

scholarly journals The microfluidic laboratory at Synchrotron SOLEIL

2020 ◽  
Vol 27 (1) ◽  
pp. 230-237
Author(s):  
Igor Chaussavoine ◽  
Anthony Beauvois ◽  
Tiphaine Mateo ◽  
Ramakrishna Vasireddi ◽  
Nadine Douri ◽  
...  
Keyword(s):  
Soft Lithography ◽  
Light Sources ◽  
Microfluidic Chips ◽  
Liquid Sample ◽  
Microfluidic Systems ◽  
Time Resolved ◽  
Liquid Environment ◽  
X Ray ◽  
Physical Chemical ◽  
Biological Phenomena

A microfluidic laboratory recently opened at Synchrotron SOLEIL, dedicated to in-house research and external users. Its purpose is to provide the equipment and expertise that allow the development of microfluidic systems adapted to the beamlines of SOLEIL as well as other light sources. Such systems can be used to continuously deliver a liquid sample under a photon beam, keep a solid sample in a liquid environment or provide a means to track a chemical reaction in a time-resolved manner. The laboratory provides all the amenities required for the design and preparation of soft-lithography microfluidic chips compatible with synchrotron-based experiments. Three examples of microfluidic systems that were used on SOLEIL beamlines are presented, which allow the use of X-ray techniques to study physical, chemical or biological phenomena.

Liquid PMMA: A High Resolution Polymethylmethacrylate Negative Photoresist as Enabling Material for Direct Printing of Microfluidic Chips

2017 ◽  
Vol 20 (2) ◽  
pp. 1700699 ◽  
Author(s):  
Frederik Kotz ◽  
Karl Arnold ◽  
Stefan Wagner ◽  
Werner Bauer ◽  
Nico Keller ◽  
...  
Keyword(s):  
High Resolution ◽  
Microfluidic Chips ◽  
Negative Photoresist ◽  
Direct Printing

scholarly journals Using the Taguchi-Genetic Algorithm to Improve Lithographic Photoresist Operating Conditions of Touch Panels to Upgrade After-Develop Inspection

2018 ◽  
Vol 8 (12) ◽  
pp. 2382
Author(s):  
Meng-Hua Li ◽  
Shen-Tsu Wang
Keyword(s):  
Genetic Algorithm ◽  
Optimum Parameter ◽  
Operating Conditions ◽  
Control Factor ◽  
Process Conditions ◽  
Negative Photoresist ◽  
Forming Process ◽  
Touch Panel ◽  
Positive Photoresist ◽  
Touch Panels

In order to use touch control products more conveniently, a general objective is to develop lighter and smaller touch panels. A touch panel using the one glass solution (OGS) is an important development. The black matrix (BM) in an OGS touch panel is used as a black frame. The photoresist is divided into a positive photoresist and a negative photoresist. The BM photoresist is negative. After coating, exposure, and development in the BM process, after-develop inspection is implemented to check if the appearance is abnormal. It is quite difficult to rework the negative photoresist process. There is still room for improving the BM photoresist process capability Cpk. Thus, in order to reduce the customer complaint rate and enhance stability, the photolithography process is improved to enhance Cpk. Among the BM black negative photoresist forming process conditions of OGS products, the pre-baking time is the most important process control factor. The method set up herein improves the original Cpk = 0.90. This study employs the fast messy genetic algorithm (fmGA) to select the optimum orthogonal array of the Taguchi method, so as to implement the decision process of optimum parameter design. The Cpk of the optimum parameter is 2.12.

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