Development and testing of hand exoskeletons

Robotics is increasingly involving many aspects of daily life and robotic-based assistance to physically impaired people is considered one of the most promising application of this largely investigated technology. However, as of today, hand exoskeletons design can still be considered a hurdle task and, even in modern robotics, providing assistance to those patients who have lost or injured their hand skills, assuring them an independent and healthy life through the design of exoskeleton technologies is, surely, one of the most challenging goal. In this framework, the research activity carried out during the PhD period concentrated on the development of wearable devices, with special focus given to hand exoskeletons which support patients suffering from hand disabilities during the Activities of Daily Living (ADLs). The studied devices have been designed to be also used during rehabilitative sessions in specific tasks trying to restore the dexterity of the user's hands. Starting from current solutions identified within the state of the art, the work was conducted heading to the development of portable, wearable and highly customizable devices. The last aspect will be fully endorsed by the definition of patient-centered design strategies leading to tailor-made devices specifically developed on the users' needs. Two hand exoskeletons solutions will be presented throughout the thesis. The first consists of a compact and lightweight solution which exploits a novel 1-DOF kinematic chain of the finger mechanism to accurately reproduce the physiological finger trajectory. The applicability of topology optimization to the wearable technologies field has then been deeply investigated in the design of the second exoskeleton, which has yielded a high-performance aluminum-alloy solution. The performance of the resulting systems was evaluated by means of simulations and tested during experimental validation campaigns by producing several prototypes which allowed to assess their effectiveness in a real-use scenario; the obtained results were satisfying, indicating that the derived solutions may constitute a valid alternative to existing hand exoskeletons so far studied in the rehabilitation and assistance fields.