Mechanical metamaterials actuators achieve pre-determined input-output operations exploiting architectural features encoded within a single 3D printed element, thus removing the need of assembling different structural components. Actuators are currently used in many applications from machines to robots. Designing materials with tailored mechanical properties and functionality still remains a great scientific and technological challenge, with huge potential for engineering applications and societal gains. A revolutionary approach of recent years has been to focus on materials that are structured on the macroscale producing mechanical metamaterials, a novel class of artificial materials engineered to have exceptional properties and responses that are difficult to find in conventional materials. These peculiar properties find natural applications in industrial design, as architectural motifs or reinforcement patterns for textiles, beams and other structures. The increased focus on metamaterials is stimulated by the recent advances in digital manufacturing technologies, such as 3D printing, which enable an easier design of such material structures with the removal of many of the constraints in scale and geometry at low cost. In metamaterials actuators, constituent cells work together in a well-defined order to obtain a desired macroscopic movement. Current design strategies for metamaterial structures and machines are essentially based on manual operations, but the METADESIGN project showed that that automatic algorithms can improve considerably the design process leading to more efficient actuators. The project resulted in a set of tested and 3D printed actuators working in two and three dimensions, producing motion in various linear directions, as well as rotatory motion, in response to localized uniaxial compression. These development lead to three publications in high impact journals. The technology behind the METADESIGN project was protected by an Italian patent claim and an international TCP extension, both still pending. The project results were also disseminated thanks to the development of an effective pitch deck, a graphical identity and a web site. The commercialization strategy is currently based on licencing the software and the project team is currently looking for potential customers and industrial partners. The research and development effort is continuing also beyond the end of the METADESIGN project thanks to a grant from the Italian Ministry of Economic Development aiming at elevating the Technology Readiness Level of the technology.
