|dc.description.abstract||In this study, Poly Methyl Methacrylate (PMMA) was used as the substrate
for microfluidic devices. and the micro-milling process of the microfluidic device
is carried out by a high-precision five-axis Computer Numerical Control (CNC)
machine. After the micro-milling , the surface will have milling traces and burrs.
which has a certain impact on microfluidic devices. The milling traces can
deteriorate the surface roughness, and the burrs in the microfluidic channel can
cause changes in the flow direction of the liquid or the formation of air bubbles.
Therefore, I investigate the parameters of micro-milled polymers first, and
understand the influence of processing parameters on surface roughness and
burrs. We try to optimized to produce high-quality chips with low surface
roughness and small burr size. By understanding the machining limits of micromilling processing,( The processing machine can process the smallest partition
wall thickness and the deepest processing depth、micropillar features with high
aspect ratios…) Use five-axis CNC to create smaller scales and complex graphic
features that cannot be produced with other equipment. In CNC direct milling to
manufacture microfluidic dies, the smallest feature size is limited by the existing
tool size .( milling cutter’s diameter :width、milling cutter’s length :depth)
Plastic and metal can be manufactured for inverted feature as micro-mold turning
PDMS or hot pressing to create microfluidic patterns that cannot be machined by
direct milling. Then can enables a variety of chip production.
At the back end is the bonding process, as there is no perfect thermoplastic
bonding process currently. Each bonding method has its own advantages and
disadvantages. According to the needs of each microfluidic chip, select its
suitable bonding method, and present the different devices that can be completed
one by one. in this study, in addition to discussing the influence of milling
parameters on burrs and surface roughness, the ability of micro-milling is
discussed by manufacturing inverted feature as micro-mold. Finally, the suitable
bonding method is selected according to the design and needs of each microchannel. We hope to provide a precision five-axis CNC micro-milling as the key
to the front-end process, perform high-precision and micro-complex feature
structure processing, and achieve the manufacture of a small number and variety
of microfluidic devices.