Biologically inspired path-controlled linear locomotion of polymer gel in air.

A novel approach based on electrohydrodynamic behavior of a dielectric liquid pattern in electric field was developed to fabricate a poly(vinyl alcohol)/dimethyl sulfoxide (PVA/DMSO) gel electromechanical system. Driving experiments indicate that this system could be well-operated in air by using a direct current (DC) electric field, and the gel exhibits a long-range path-controlled snaillike or snakelike motion with a fast crawling speed of 14.4 mm/s. Some factors, such as the applied electric field and the mass of the gel on the average crawling speed of the gel at linear path and curvilinear path, are investigated. Furthermore, a transition between snaillike gaits and snakelike gaits of the gel is also further studied in this system. The mechanism analysis suggests that this path-controlled motion of the gel arises from the drag of the spatial varied shear force F originated from the electrohydrodynamic flow of the solvent in and out of the gel.