Three-dimensional robotic structures fabricated and powered entirely with proteins.

Assembling and upscaling biomolecular activity to perform work in man-made devices is a challenge in synthetic biology. Here we report the step-by-step process to construct fully protein-based micro-three-dimensional (3D) printed robotic structures, which are coated with and actuated by a minimal actomyosin cortex. This approach can be used to program self-powered soft robots assembled from multiple biomolecular modules, devising biophysical assays to quantify active forces produced in 3D and engineering smart 3D microchips for synthetic cell assembly. The procedure covers the establishment of 3D printing microstructures from protein materials, the assembly of actomyosin-based active coatings and the robotic structure design and characterization. The detailed step-by-step instructions will guide scientists in replicating the preparation procedures, facilitating the adoption of biomolecular microrobots and the development of 3D protein-based robotic technology and their applications. The procedure is suited for users with expertise in biomaterials and requires 15 d to complete.