Characterization of mixing performance for bio-mimetic silicone cilia

This article presents the mixing performance of bio-mimetic cilia in a circular microchamber that is compatible with microwell plates. The mixing performance is characterized and compared with those of both diffusion- and vibration-induced mixers. To represent the mixing performance, the 90% mixing time, which was the time span for 90% mixing completion, was measured by analyzing the mixing process of black ink with water. The cilia mixer reduced the 90% mixing time by 8.0- and 1.4 times compared with those of the diffusion- and vibration mixers, respectively. In addition, the coefficient of variation of the 90% mixing time for the cilia mixer was reduced by 3.1- and 2.8 times compared with those of the diffusion- and vibration mixers, respectively. The experimental mixing performance was validated by numerical analysis. The simulations showed that the cilia mixer could significantly reduce the coefficient of variation because the convective flows generated by the cilia rapidly increased the surface area of the ink and thus rapidly decreased the variations in the initial mixing conditions.