  Machines that mimic humans have inspired scientists for centuries.
Bio-inspired soft robotic hands are a good example of such an endeavor,
featuring intrinsic material compliance and continuous motion to deal with
uncertainty and adapt to unstructured environments. Recent research led to
impactful achievements in functional designs, modeling, fabrication, and
control of soft robots. Nevertheless, the full realization of life-like
movements is still challenging to achieve, often based on trial-and-error
considerations from design to fabrication, consuming time and resources. In
this study, a soft robotic hand is proposed, composed of soft actuator cores
and an exoskeleton, featuring a multi-material design aided by finite element
analysis (FEA) to define the hand geometry and promote finger's bendability.
The actuators are fabricated using molding and the exoskeleton is 3D-printed in
a single step. An ON-OFF controller keeps the set fingers' inner pressures
related to specific bending angles, even in the presence of leaks. The FEA
numerical results were validated by experimental tests, as well as the ability
of the hand to grasp objects with different shapes, weights and sizes. This
integrated solution will make soft robotic hands more available to people, at a
reduced cost, avoiding the time-consuming design-fabrication trial-and-error
processes.
