Microfluidic device for automated generation of toroidal-like spheroids

In the field of tissue engineering, it is called for to automate generation of various-shaped spheroids. We propose a micro fluidic device that generates rotational flow for producing toroidal-like spheroid. This paper reports the concept of construction of toroidal-like spheroid, designs of microchannels, and fundamental verification about generation of rotational flow in the device using simulation and experiment using created microchannels. Concept of construction is non-contact operation in a continuous flow stimulus by using centrifugal force of rotational flow. Designs of the micro fluidic device was optimized to generate micro-rotational flow, and the results of flow simulation models show that rotational flow is generated at the flow velocity more than fixed. We made these designs. The large size channel was made with 3D printer and the small channel was made by poly-dimethysiloxane (PDMS) molding, and generation of rotational flow was observed in an experiment using particles. In both types of channels, particles were rotated similar to the simulations.