Magnetic/thermo dual-sensitive hydrogel-based 3D Printable millirobots

Creatures in nature complete deformation and movement through the anisotropic stretching of muscles. Soft materials for artificial muscles, such as hydrogels, need to be fabricated into anisotropic complex structures. 3D printing is an excellent manufacturing method. However, traditional hydrogels cannot be prepared by inkjet printing because of their physical properties. Here, a novel magnetic thermo-sensitive hydrogel and a non-thermo-sensitive hydrogel that can be 3D printed were synthesized. A bilayer beam as thermal deformation unit was formed by two types of hydrogels. 2D and 3D anisotropic deformable structures can be fabricated by 3D printing. In addition, we navigate the hydrogel structure out of the maze through the magnetic field. Finally, the 3D-printed structures were shown to be magnetically actuated while having more flexible thermo-responsive deformations. Dual-sensitive hydrogels have the printability to produce more flexible, precise, and perfect multi-function robots in the future, and will promote the application in the fields of micromanipulation and medical treatment.