Experiments Of3D Microfluidic Devices Based On Capillary Tubes

Microfluidic is a new interdisciplinary technology related to chemistry, physics, biology, engineering et al, with characteristics of low cost, high precision, quick react. Every droplet is a single reactor, which can prevent cross contamination. Now microfluidic is widely used genetic testing, cell encapsulation, drug delivery, tissue engineering, polymerase chain reaction (PCR) et al. We simply describe advantages and current state of microfluidic, present some manipulation technology and application of it.First of all, we report some fabricate method and materials of microfluidic chips, point their advantages and disadvantages. We describe soft lithography method using PDMS (polydimethylsiloxane) and SU-8in detail and do some experiments with these PDMS chips.Furthermore, we result some dimensionless number and production methods of micro droplets. We describe some "off-the-shelf" devices which are easily assembled/disassembled, low cost, resistant to high pressure, durable, easy to clean. These commercial devices generally used as biological assembly connectors, can successfully produce highly uniform droplets. We also do some comparisons between these connectors and traditional PDMS chips. For all microfluidic chips, when the dispersed phase flow rate is constant, higher flow rate ratio means smaller droplets.Moreover, we describe some knowledge of double emulsions and do some experiments. We describe capillary microfluidic devices for droplet fission. The size and relative size of daughter droplets can be easily controlled by adjusting flow rates and the length of the glass capillary tube. We also do some simulations of the droplet fission progress.Finally, we do some introductions of digital droplet PCR (ddPCR). We describe three main progresses of ddPCR:droplet production, DNA amplification, detection, point matters need attention and do some result analysis.