Improving Robot Grasping with a Simple Sponge
Scientists from the University of Bristol have discovered that a basic sponge can enhance robot grasping. This innovative sponge-jamming device mimics the delicate touch of a human, allowing stiff robots to handle fragile items with care.
The Significance of Variable Stiffness
While robots can perform impressive feats of agility, their rigidity makes it difficult for them to handle delicate objects like eggs. Variable stiffness devices offer a potential solution by providing contact compliance on hard robots to reduce damage or enhance the load capacity of soft robots.
A recent study presented at the IEEE International Conference on Robotics and Automation (ICRA) 2023 demonstrates that variable stiffness can be achieved using a silicone sponge.
The Human-Like Grasp
Lead author Tianqi Yue from Bristol’s Department of Engineering Mathematics highlights the importance of softness, or stiffness, in contact scenarios. Unlike robotic arms, which lack flexibility, humans possess soft tissues surrounding rigid bones, acting as a natural mechanism to protect delicate objects.
In this research, a soft device with variable stiffness was developed to be attached to the end of a robotic arm, enabling safe and gentle contact with objects.
The Versatility of Silicone Sponge
Silicone sponge proves to be an ideal material due to its low cost and ease of fabrication. Similar to everyday cleaning sponges, it is a porous elastomer. When squeezed, the sponge stiffens, allowing it to transform into a variable-stiffness device.
The applications for this innovation are wide-ranging. It can be used in industrial robots to handle delicate substances like jellies and eggs, as well as in service robots to ensure safer interaction with humans.
According to Mr. Yue, “This cheap and nimble silicone-sponge based device enables robots to achieve gentle contact with objects. Its potential lies in its affordability and lightweight design.”
Furthermore, the team plans to enhance the device’s variable stiffness capabilities in multiple directions, including rotation.