EleTac: An elephant-inspired soft robotic gripper with a sophisticated sense of touch

Researchers led by Professor Van Anh Ho at the Japan Advanced Institute of Science and Technology developed EleTac, a soft robotic gripper modeled on the tip of an elephant trunk. The device uses two soft fingers driven by pneumatic pressure, allowing them to close gently around objects. Its central sensing approach avoids distributing many conventional sensors through material that must continually bend and stretch. Instead, one fisheye camera inside the gripper observes deformation of the soft structure during grasping.

Deep-learning algorithms trained on these internal images extract tactile information, including external contact, and proprioceptive information about the gripper's own shape, position, and movement. The researchers describe this combination as high-resolution tactile sensing and proprioception. Soft grippers are of interest because their flexible materials can conform to varied shapes and may be better suited than rigid designs to handling delicate items such as fruit, baked goods, laboratory samples, and medical supplies. Integrating sensors without reducing flexibility or limiting sensing coverage has been a major challenge.

In evaluations using a simple control strategy, EleTac grasped objects including fruit, tofu, fabric, tools, bolts, and playing cards. It was also tested in a touch-only task that located and pulled a pen from sand. In another experiment, it wiped marker ink from curved tableware using a sponge, adjusting its motion according to the sensed pressure between sponge and surface.

The team considers the gripper compact, lightweight, and low cost, and says it could serve as a plug-and-play end effector for existing robotic platforms and humanoid robots. The researchers see potential for delicate industrial and business tasks and, longer term, for service robots assisting with everyday activities in homes, hospitals, and public spaces.