An easy-to-make sponge-jamming device can help stiff robots handle delicate items carefully by mimicking the nuanced touch, or variable stiffness, of a human. Robots can skip, jump and do somersaults, but they’re too rigid to hold an egg easily. Variable-stiffness devices are potential solutions for contact compliance on hard robots to reduce damage, or for improving the load capacity of soft robots.
This study shows that variable stiffness can be achieved by a silicone sponge. In the paper, the authors explain how they developed a soft device with variable stiffness, to be mounted on the end robotic arm for making the robot-object contact safe. Silicone sponge is a cheap and easy-to-fabricate material. It is a porous elastomer just like the cleaning sponge used in everyday tasks. By squeezing the sponge, the sponge stiffens which is why it can be transformed into a variable-stiffness device.
This device could be used in industrial robots in scenarios including gripping jellies, eggs and other fragile substances. It can also be used in service robots to make human-robot interaction safer.
“A Silicone-sponge-based Variable-stiffness Device” by Tianqi Yue at the IEEE International Conference on Robotics and Automation (ICRA) 2023.