UNIQUE-HAND project

Background

The design of artificial hands has had a considerable development in the last decades, pushed forward by the need to improve existing solutions for people with a limb loss and because of the increasing importance of robotic grasping and collaborative robotics. Anthropomorphic designs, similar to the human hand, are convenient for prosthetic applications due to evident aesthetic reasons. They could also deal with a greater variety of objects and grasping modes and allow to reduce tool changes in industrial environments and to provide versatility to assistive robotic arms, like those attached to wheelchairs of disabled people. However, it is impossible to replicate the complexity of the human hand with current technology. Low-cost and simplicity are important goals in artificial hand design, enabling accessibility to developing countries and people with low incomes, as initiatives such as the Open Hand Project or Enabling the Future have shown. They can also contribute to widespread exponentially collaborative robotic applications, running in parallel to the implementation of Industry 4.0. The two editions of the Cybathlon Arm Race in 2016 and 2020 have shown that simple hands with a low number of degrees of freedom can surpass more sophisticated designs in terms of final performance. Previous studies developed in our research group have also shown that a fraction close to 80% of the variability observed in human grasping in activities of daily living, can be adequately represented by five synergies and that only two synergies are necessary to represent 80% of the the variability observed in the tendon actuation of an artificial hand with six degrees of freedom moved by healthy subjects. Hence, in this project we rely on the hypothesis that a unified design for an affordable hand, with a limited number of degrees of freedom and anthropomorphic appearance can be a good solution for both prosthetic and collaborative robotic applications. 

The related work previously developed by the team in the framework of projects DEVALHAND (2014-2016) (https://sites.google.com/a/uji.es/devalhand/) and BENCH-HAND (2017-2020)  (https://sites.google.com/a/uji.es/bench-hand/), pave the way for achieving this goal and for applying suitable design and testing methods developed in those projects to the development of this new hand.