Highly productive droplet formation by vertical elongation of focused laminar flow in microchannel
Chemical Product Design and Engineering (CPD&E)
Chemical Product Design & Engineering - Poster (CPD&E - P)
Keywords: droplet formation,microchannel,flow-focusing,vertical elongation,integration
Authors : Daisuke SAEKI†‡, Shinji SUGIURA*†, Teruhiko BABA†, Toshiyuki KANAMORI†, Seigo SATO‡, Sukekuni MUKATAKA‡, Sosaku ICHIKAWA‡
†Research Center of Advanced Bionics, National Institute of Advanced Industrial Science and Technology (AIST), Central 5th, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
‡Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan
*shinji.sugiura@aist.go.jp
Micrometer scaled water-in-oil droplets have been widely applied in food, pharmaceutical, and chemical industries, and recently also studied as microreactors. Droplet formation with microdevices creates new opportunities to fabricate these finechemical materials, for example, microcapsules, polymerized particles, and multi phase polymer beads. Preparation techniques of monodisperse droplets have been proposed using two- or three-dimensional structures such as a T-junction, flow-focusing structure, and nozzle. However, productivity of the previously reported methods is too low for the industrial application. A flow-focusing structure with channel expansion is one of the promising structures to produce droplets reproducibly. In order to improve productivity, integration of multiple droplet production channels is important. In this study, we propose parallelization of droplet-forming channels with vertical elongation of a focused laminar flow. We designed the novel microchannel structure, in which multiple streams of aqueous phase are formed in a laminar flow of oil phase at the upstream area, and the aqueous phase streams are vertically elongated by changing microchannel depth at the downstream area. The microchannels were prepared with PDMS by softlithography technique. At first, we investigated the effect of vertical elongation and flow rate on droplet formation by a single aqueous phase stream. By applying the vertical elongation of flow, we could produce water-in-oil droplets with the faster aqueous phase flow rate rather than that without the vertical elongation structure. Furthermore, by parallelizing this structure, we have successfully produced droplets from parallel aqueous phase streams more efficiently. These results show the possibility to improve productivity of flow-focusing droplet formation technique for future industrial application.
Presented Wednesday 19, 13:30 to 15:00, in session Chemical Product Design & Engineering - Poster (CPD&E - P).
