摘要
Microfluidic droplets have emerged as novel platforms for chemical and biological applications. Manipulation of droplets has thus attracted increasing attention. Different from solid particles, deformable droplets cannot be efficiently controlled by inertia-driven approaches. Here, we report a study on the lateral migration of dual droplet trains in a double spiral microchannel at low Reynolds numbers. The dominant driving mechanism is elucidated as wall effect originated from the droplet deformation. Three types of migration modes are observed with varying Reynolds numbers and the size-dependent mode is intensively investigated. We obtain empirical formulas by relating the migration to Reynolds numbers and droplet sizes. The effect of droplet deformability on the migration and the detailed migration behavior along the double spiral channel are discussed. Numerical simulations are also performed and yielded in qualitative agreement with the experiments. could be a promising alternative to existing inertia-driven approaches bio-particles. This proposed low Re approach based on lateral migration especially concerning deformable entities and susceptible
Microfluidic droplets have emerged as novel platforms for chemical and biological applications.Manipulation of droplets has thus attracted increasing attention.Different from solid particles,deformable droplets cannot be efficiently controlled by inertia-driven approaches.Here,we report a study on the lateral migration of dual droplet trains in a double spiral microchannel at low Reynolds numbers.The dominant driving mechanism is elucidated as wall effect originated from the droplet deformation.Three types of migration modes are observed with varying Reynolds numbers and the size-dependent mode is intensively investigated.We obtain empirical formulas by relating the migration to Reynolds numbers and droplet sizes.The effect of droplet deformability on the migration and the detailed migration behavior along the double spiral channel are discussed.Numerical simulations are also performed and yielded in qualitative agreement with the experiments.This proposed low Re approach based on lateral migration could be a promising alternative to existing inertia-driven approaches especially concerning deformable entities and susceptible bio-particles.
基金
supported by the National Natural Science Foundation of China(Grant Nos.11572334,11272321 and 11402274)
