Electrically Driven Hydrogel Actuators From Turgor Pressure to Ciliary Motion

ABSTRACT Electrically driven hydrogels convert ion migration, water transport, and polymer network deformation into mechanical outputs, offering a soft and responsive platform for actuation. Recent progress in this field has advanced from macroscopic electroosmotic turgor actuators to micrometer‐scale hydrogel cilia arrays. Membrane‐confined polyelectrolyte gels retain osmotic pressure and transform swelling into large blocking stress, while electroosmotic flow accelerates water uptake through charged polymer meshes. In comparison, two‐photon‐printed gel microcilia with nanometer‐scale hydrogel networks shorten ion migration distance and generate low‐voltage bending, rotational motion, and reprogrammable collective actuation through microelectrode arrays. This News & Views examines how structural design regulates the output of hydrated charged polymer networks from load‐bearing actuation to dynamic fluid manipulation, highlighting the significance of electrically driven hydrogel actuators for soft robotics, microfluidics, and biomimetic micromachines.