Since the advent of micro-gas chromatography in 1979, microfluidic technologies have been developing rapidly. The reason for this success is due to the unique chemical and physical features that occur in fluids at the micro/nano-size, which allowing for several advantages over conventional “macro”-techniques. Compared to the first materials used to fabricate microfluidic devices such as: silicon and glass, thermoplastics is becoming a popular choice with benefits including a wide range of material properties, low material costs, and compatibility with manufacturing methods which are scalable from laboratory prototyping to full scale mass production.
For the fabrication procedure of thermoplastic microfluidic chips, bonding is a critical step to produce the final enclosed fluidic paths. A variety of bonding methods for thermoplastic microfluidics have developed such as: adhesive bonding, thermal fusion bonding, solvent bonding, microwave welding, ultrasonic welding, and etc. Among these methods, solvent bonding has been proven as a rapid, highly effective, and high throughput method for the sealing of microchannels on thermoplastic substrates. The significant advantage of solvent bonding is possible to create a strong bond even at low temperatures with a minimum of equipment.
Based on the two actual needs: (1) addressing the lack of optical transparency required for tasks involving quantification of most existing 3D printed device, while the use of this technology in fabricating microfluidics is attracting considerable interest thanks to its low cost, rapid prototyping, and ability to realize complex structures; and (2) the highly attention to cyclic olefin copolymer (COC) material with high optical clarity into the deep-UV range, low water absorption, and exceptionally good resistance to a host of solvents including organics such as acetonitrile commonly used in liquid chromatography, a study of solvent-based bonding methods has developed to address the proposed needs through the bonding of (1) PMMA/PLA, PMMA/ABS; and (2) COC/COC substrates. To analysis the bonding quality, several experiments were conducted including: leakage test, burst test, cross-sectional investigation using microscopic, SEM, and the measurement of UV/VIS transmissivity. The experiment results clearly showed that the proposed bonding schemes successfully formed a strong bond between PMMA/PLA, PMMA/ABS, and COC/COC thermoplastic substrates, without sacrificing their intended functionalities.

Since the advent of micro-gas chromatography in 1979, microfluidic technologies have been developing rapidly. The reason for this success is due to the unique chemical and physical features that occur in fluids at the micro/nano-size, which allowing for several advantages over conventional “macro”-techniques. Compared to the first materials used to fabricate microfluidic devices such as: silicon and glass, thermoplastics is becoming a popular choice with benefits including a wide range of material properties, low material costs, and compatibility with manufacturing methods which are scalable from laboratory prototyping to full scale mass production.
For the fabrication procedure of thermoplastic microfluidic chips, bonding is a critical step to produce the final enclosed fluidic paths. A variety of bonding methods for thermoplastic microfluidics have developed such as: adhesive bonding, thermal fusion bonding, solvent bonding, microwave welding, ultrasonic welding, and etc. Among these methods, solvent bonding has been proven as a rapid, highly effective, and high throughput method for the sealing of microchannels on thermoplastic substrates. The significant advantage of solvent bonding is possible to create a strong bond even at low temperatures with a minimum of equipment.
Based on the two actual needs: (1) addressing the lack of optical transparency required for tasks involving quantification of most existing 3D printed device, while the use of this technology in fabricating microfluidics is attracting considerable interest thanks to its low cost, rapid prototyping, and ability to realize complex structures; and (2) the highly attention to cyclic olefin copolymer (COC) material with high optical clarity into the deep-UV range, low water absorption, and exceptionally good resistance to a host of solvents including organics such as acetonitrile commonly used in liquid chromatography, a study of solvent-based bonding methods has developed to address the proposed needs through the bonding of (1) PMMA/PLA, PMMA/ABS; and (2) COC/COC substrates. To analysis the bonding quality, several experiments were conducted including: leakage test, burst test, cross-sectional investigation using microscopic, SEM, and the measurement of UV/VIS transmissivity. The experiment results clearly showed that the proposed bonding schemes successfully formed a strong bond between PMMA/PLA, PMMA/ABS, and COC/COC thermoplastic substrates, without sacrificing their intended functionalities.

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