"Additive manufacturing technologies such as 3D printing of polymers and metals have a large impact in many sectors. In this project we propose to explore ways to develop and commercially exploit a new type of 3D printing tool for manufacturing of silicon nanostructures. These 3D printers will make it possible to design and implement silicon micro- and nano-electromechanical system (MEMS&NEMS) sensors and photonic components in low volumes at affordable costs. As a result, resource-intensive semiconductor clean-room infrastructure will no longer be required to design and implement MEMS, NEMS and photonics components. A 3D printer for silicon nanostructures is made possible by employing a novel additive layer-by-layer manufacturing process that has been developed within the ERC Starting Grant project M&M´s (No.277879) lead by the PI. This process is based on alternating steps of chemical vapour deposition (CVD) of silicon and local implantation of gallium ions by focused ion beam (FIB) writing. In a final step, the defined 3D structures are formed by etching the silicon in potassium hydroxide (KOH), where the ion implantation provides the etching selectivity. The feasibility of the technology has been demonstrated within the ERC-M&M´s project by forming 3D silicon structures with layer thicknesses of 40 nm and lateral dimensions as small as 30 nm. To implement a 3D printer that can manufacture 3D silicon nanostructures from computer-generated 3D graphics, the steps of focused ion beam (FIB) writing and silicon deposition have to be combined as a fully automated switched process in a single tool."