Mixing of solutions by coordinated ciliary motion in Vorticella convallaria and patterning method for microfluidic applications

Biological motors from living microorganisms might be applicable in microsystems while reducing the overall size of devices. We used directional fluid transport induced by coordinated ciliary motion in living Vorticella convallaria microorganisms for microfluidic applications. As an example of its application, fluid transport was applied to enhance the mixing of solutions containing microparticles in a microchannel that had been functionalized with V. convallaria. Particle transport by several cells of V. convallaria enhanced mixing. Changes in intensity profiles and mixing indexes were measured along the flow direction. Decreasing the flow speed enhanced the mixing performance. We developed a method to pattern V. convallaria in micropockets to extend the possibilities for device design. A three-layer device equipped with a pneumatic valve enables confinement of V. convallaria with removal of the suction pressure. Most trapped cells adhered in the pockets for 6 h. The pocket geometry controlled the V. convallaria posture. Application of the coordinated ciliate motion is expected for portable bioanalytical systems capable of analyzing less-diffusive materials.