Microstructures are often restricted to 2D-(or 2.5D) structures and are generated by mask-based or template-based processes. This, however, limits the design space available for the actuators signifi-cantly. A process which is designed to generate 3D microstructures by direct writing is two-photon lithography (2PL), mostly based on 2Photon polymerization (2PP). Recently, we developed a new process, two-photon crosslinking (2PC). In 2PC, two photon absorption is used to trigger a C,H insertion reaction within the focal volume. The activated chromophore can react with neighbouring C,H groups on polymer chains leading to crosslinking or C,H groups on the substrate surface, leading directly to covalent immobilization of the forming microstructure.