Although much has been done for developing technologies to bear upon problems of individuals with sensorimotor impairments, the impact of robotic aids on people with real needs in the real world is still very limited. Our main goal is to increase the cumulative benefits of assistive robotic technologies to society by enhancing their effectiveness AND the number of beneficiaries. The challenge is to increase both multipliers in the “performance times accessibility” product, subverting the traditional situation where one factor can only be increased at the expense of the other. We believe this is possible by investigating how the artificial can physically interact and effectively “talk to” the natural. Understanding such a “language” is crucial not only to improve performance of rehab technology, but also to tackle the most difficult problem of making it “simple enough” to be effective and accessible. We possess good clues about such a language, whose words we believe are sensorimotor synergies, and have the scientific competence to further its understanding and the technological prowess to translate it into a new generation of robotic assistive devices.We know that a central ingredient for the applicability of synergy-based models to physical human-machine interaction is impedance adaptability, i.e. soft robotics technologies. We will develop soft synergy-based robotics technologies to produce new prostheses, exoskeletons, and assistive devices for upper limb rehabilitation.Building on solid methodological bases, this project will have a significant social impact in promoting advanced robot prosthetic and assistive technology, while introducing disruptively new, admittedly risky, but potentially high-impact ideas and paradigms, such as the proposed pioneering work on supernumerary limbs for assistance and rehabilitation to motor impairments of the upper limb.