Micro-mixing of highly viscous bio-samples using orbital shaking

Micro-mixing of highly viscous bio-samples is considered. Existing methods mix bio-samples by only shaking micro-wells or by specially designed micro-stirrers which are ineffective or unapplicable for highly viscous materials, letting alone small volumes at microliter or nanoliter level. Our method mixes viscous bio-samples in micro-wells using orbital shaking plus an innovative block which is built in with micro-channels. In this paper, the design of the block is presented, the flow of the bio-samples in the micro-channel under orbital shaking is developed, the Reynolds number of the flow in the micro- channel is calculated, and the dynamics of the mixing process is analyzed. Finally experiment results of mixing monoolein with water are presented. In each trial, X-ray diffraction is used to evaluate the results of mixing which confirm that the proposed approach is effective for mixing highly viscous bio-samples.