Droplet-based microfluidics for generation of alginate beads and encapsulation of particles

• Main Authors: Lung-Sheng Tseng, 曾隆盛
• Other Authors: 陳志敏
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/mdt52h

碩士 === 國立中興大學 === 機械工程學系所 === 99 === This experimental study employs the flow-focusing micofluidics to produce gelatinized droplets containing calcium alginate to serve as a platform for future bio-sensing research. The microfluidics was made of Polydimethylsiloxane (PDMS) using the soft lithography technique. The sodium alginate solution (0.05-0.15% w/v) and calcium chloride (50 mM) solution were brought together with a Y-junction into the microfluidics as the dispersed phase. The dispersed fluids then encounter the continuous phase of oil at the cross junction to form the water-in-oil droplets. The cross junction is followed by a serpentine shaped channel in order to enhance the mixing and reaction of the two solutions inside the droplet. It is found that the droplet size ranging from 57 to 116 μm in diameter can be generated by decreasing the continuous phase flow rate from 0.05 to 0.02 ml/hr at a fixed dispersed phase flow rate of 0.005 ml/hr. The size of droplets remains nearly unchanged by the variation of sodium alginate concentration between 0.05-0.15% (w/v) but the higher concentration may become over gelatinized causing channel blockage. The alginate droplets can be aligned into one or multiple rows in an expanded channel region. The pattern of droplet alignment depends on the flow rate of continuous phase. The present technique was further used to generate and manipulate alginate droplets that encapsulated fluorescence particles.