  Stiffness variation and real-time position feedback are critical for any
robotic system but most importantly for active and wearable devices to interact
with the user and environment. Currently, for compact sizes, there is a lack of
solutions bringing high-fidelity feedback and maintaining design and functional
integrity. In this work, we propose a novel minimal clutch with integrated
stiffness variation and real-time position feedback whose performance surpasses
conventional jamming solutions. We introduce integrated design, modeling, and
verification of the clutch in detail. Preliminary experimental results show the
change in impedance force of the clutch is close to 24-fold at the maximum
force density of 15.64 N/cm2. We validated the clutch experimentally in (1)
enhancing the bending stiffness of a soft actuator to increase a soft
manipulator's gripping force by 73%; (2) enabling a soft cylindrical actuator
to execute omnidirectional movement; (3) providing real-time position feedback
for hand posture detection and impedance force for kinesthetic haptic feedback.
This manuscript presents the functional components with a focus on the
integrated design methodology, which will have an impact on the development of
soft robots and wearable devices.
