Microstructures Fabricated by Two‐Photon Polymerization and Their Remote Manipulation Techniques: Toward 3D Printing of Micromachines

As a promising microfabrication method, two‐photon polymerization (TPP) underwent a rapid development for various applications in chemistry, biology, pharmaceuticals, microfluidics, and so forth. In recent years, the method has received particular attention because of its application for micromachines, including those requiring remote manipulation. Different manipulating techniques such as magnetic, optic, and acoustic manipulation are realized on TPP‐fabricated microstructures, demonstrating the great potential for further development of micromachines. Nonetheless, most of the work is still at early stages, only proofing conceptual ideas. For instance, magnetically driven microswimmers are only investigated in artificial experimental environments, and it is still challenging to tackle complex in vivo conditions. Although a long journey is still ahead for using these micromachines in daily life, it is predictable that the combination of two‐photon polymerization associated with remotely driven techniques will benefit various fields.