Microfluidic handling of hydrogel microfibers

This paper describes a handling method of thin (~200 μm in diameter), long (>;meter) and fragile (breaking point: ~2 μN) hydrogel microfibers in liquid. By using fluid flow and thin capillary, the hydrogel fibers can be manipulated, clamped and cut without damaging and entangling the hydrogel microfibers (we termed “microfluidic handling”). This microfluidic handling technique enables us to construct a mechanical weaving machine for cell-encapsulating hydrogel microfibers, resulting the construction of centimeter-scale woven 3D cellular structures. In addition, we demonstrated computer-controlled automatic handling of the hydrogel microfibers, indicating that the microfluidic handling would be a fundamental technique for rapid and reliable handling of fragile hydrogel microfibers containing various types of functional materials such as cells, bacteria, proteins and nanofibers.