Abstract
This paper describes self-assembled hydrogel microspring. We found that the hydrogel microspring was continuously and spontaneously formed by extruding sodium alginate pre-gel solution into calcium chloride bath using a bevel-tip microfluidic capillary. The diameter and packing density of the springs depended on the tip angle of the capillary. As a demonstration of soft actuator, we encapsulated magnetic colloids inside the hydrogel spring and successfully actuated the microspring by applying magnetic field. We believe that our method of making hydrogel microspring will be powerful approach to expand the displacement of various types of soft actuators driven by magnetic fields, electric fields, temperatures and chemical reactions.
