Fabric robot actuator switched between 4 motion modes
The fabric sleeve used button-fastened constraint modules, and an add-on tactile sensor could be placed wherever needed.
A fabric pneumatic actuator was shown switching among 4 motion modes by swapping button-fastened constraint modules on the same sleeve.
The setup let one soft robot body change behavior without being taken apart. The modes were isotropic expansion, contraction, bending, and twisting.
The same actuator body could be retuned by moving fabric parts around instead of rebuilding it.
That matters because soft actuators usually get their motion fixed by the way their chambers or reinforcements are built. Here, the motion could be reconfigured after fabrication.
The paper says the changes were quick, tool free, and reusable. In plain terms, the robot could be retuned by moving fabric parts around instead of rebuilding the actuator.
The reported performance numbers give a clearer picture. At 24 kPa, the actuator reached an elongation ratio of 1.2, a bending angle of about 60 degrees, and a twisting angle of about 90 degrees.
It also produced blocking forces above 10 N in all modes. That is the push it could resist while held still.
The system also included an attachable capacitive tactile sensor. Capacitive sensing measures changes in electric capacitance when something touches or presses the surface.
That sensor could be mounted at different spots on the actuator, depending on the task. Its capacitance rose with force, showed about 12% hysteresis, and stayed stable across repeated cycles under preload.
The paper also describes soft robotic arms built from several of these actuators. By changing the attached constraint patterns, the arms could reconfigure their motion for grasping.
What the source does not show is longer-term durability, real-world task success outside the lab, or how many cycles the buttoned fabric and sensor modules can survive before wear becomes a problem.
Source: arXiv cs.RO