A Tactile-enabled Hybrid Rigid-Soft Continuum Manipulator for Forceful Enveloping Grasps via Scale Invariant Design

Abstract

This work presents a novel hybrid rigid-soft continuum manipulator, which integrates high-resolution tactile sensing in a form factor that is forceful, compliant, inherently safe, and easily controllable. We utilize a hybrid approach motivated by scale-invariant principles to fuse the rigid and soft design domains while addressing their respective challenges. We use Euler-Bernoulli beam theory and geometric inference to design and develop a novel variant of folded flexure hinge (FFH) compliant mechanism, the variable area moment of inertia folded flexure hinge (VAFFH), which deforms logarithmically along its length and thus yields first-order scale-invariant grasp behavior. Finally, we characterize the forcefulness of the manipulator and demonstrate its compliance, adaptability, and tactile sensing capabilities in selected tasks.