The Fabrication Of Focusing Device Based On Coned Capillary And Its Preliminary Application In Generation Of Calcium Alginate Microfiber

In recent years, microfluidic spinning as a novel means has got a lot of progress in supporting the growth and response of biological systems. This paper describes the production of a simple microfluidic device for the realization of flow-focusing based on coned capillary and its application into the preparation of calcium alginate fibers, and the preliminary results on the encapsulation of chloroplasts.First of all, we proposed a technical method forthe production of a simple microfluidic device for focusing-flow, which is based on coned capillary. In order to get precision controlof the diameter of the tip on the end of coned capillary, we developed a novel microfluidic corrosion devices. Under microscope, this device couldbe applied todefinitely intercept the tip on size-demand, including the diameter of capillary tip and the length of coned capillary. For the construction of the microfluidic flow-focusing device based on the combination of coned capillary and PMMA base, we explored two different ways of fabrication, which are largely based on their distinct bonding processes : one is established on the conventional surface fabrication in which the bonding is carried on through chemical-evaporating plus loading pressure; another is based on PMMA bulk fabrication, because of its borehole-formed channels, the sealing for running microflow in the device could be simply achieved via interfacing the end of channel with fistular-bolt on gasket, with no need of the above meaning of ’bonding’. There showed that the later focusing-flow device thus-formed is not only simple and convenient, but also very robust even in larger flow-rate.Next, we explored the preparation of calcium alginate microfibers with the above fabricated microfludic flow-focusing device. With solutions of 1% sodium alginate and 2% calcium chloridewe tested the generation of microfiber under different flow-rate ratios, and explored the relationship between the microfiber diameters and the ratios. In adition, the reasons of channel clogging were discussed.Finally, using chloroplasts as samples, we preliminary tested their encapsulation amongthe meanwhile formed calcium alginate microfibers and calcium alginate- poly(vinyl alcohol) composite microfibers. We observed that the chloroplasts could bedistributed in such fibers...