화학공학소재연구정보센터
International Journal of Heat and Mass Transfer, Vol.78, 1284-1291, 2014
A numerical study on the loading of cryoprotectant cocktails-on-a-chip, Part I: Interacting miscible viscous fluids
The laminar flow in microfluidic devices has shown promise as an effective delivery mechanism for cryoprotective agents to biological cells. For this method to gain more prevalence, its potential for use with more realistic and more complicated mixtures of cryoprotectants requires further exploration. In this work, we investigate the transport phenomena associated with a cryoprotectant cocktail consisting of 1.5 M 1,2-propanediol, 1.5 M dimethyl sulfoxide, and pure water. The viscous and miscible liquids are driven through a 25-cm long microchannel by a pressure gradient with inlet flow rate as the operating parameter. Our model resolves the spatially varying viscosity field, velocity field, and the concentrations of the three chemical species. With equal flow rates at each inlet, viscous sheets are formed and span the vertical direction of the channel. Depending on which cryoprotectant is introduced at the upstream inlets, the viscous sheets can move towards the center of the channel and be surrounding by less the less viscous mixture. This causes a unique velocity profile with three maxima in the transverse direction. As the inlet flow rates are decreased, the miscible liquids are afforded more time for molecular diffusion. Further decreasing the flow rate leads to a well-mixed viscous mixture of the three chemical species. The features of this cryoprotectant loading configuration are unique and, with additional optimization, could lead to improved cell survival rates during cryopreservation. (C) 2014 Elsevier Ltd. All rights reserved.