As it discussed in previous post, soft grippers will be a new generation of grippers because of their universal application for flexible manufacturing. Soft gripper range widely from those that are working with air pressure to electrically actuated ones. We can also classify soft grippers into two groups of elephant-trunks-shaped and octopus-arms-shaped soft grippers. In this post, we will briefly introduce different kinds of soft grippers and their further application.
Beyond the use of air pressure for the simplest form of pneumatic soft grippers that we explained about in our previous post, Eric Brown Lab used the air pressure to fabricate a pneumatic universal robotic gripper based on jamming of granular materials. A griper’s actuator is an elastic bag that is filled with granular matter. When the gripper touches the surface of an object, an evacuation pump, which is connected to the bag, starts evacuating to lock granular materials around the object. The proposed system is capable of picking up objects with wide range of different sizes.
Bristol Robotics Laboratory introduced an elephant trunk-shape gripper that picks up and holds roughly cylindrical objects. This gripper consists of flexible outer shell that is filled with incompressible liquid, and is activated with two quasi-longitudinal cables. These cables are located in one side of the gripper to provide bending movements.
In out lab at Shan Research Group, we designed and implemented a soft gripper, based on air pressure, consist of three soft fingers. Each finger is separately controlled by three electrically activated tendons that capable our gripper with providing more complex motions than any other hand-shaped gripper. To date, our gripper is the first generation of grippers that enables twisting motion, just like human hands. It is completely safe for human and environment to work with the gripper since they are fabricated from body friendly flexible materials for knuckles and joints. More details about this gripper will be available soon. Would you need any further information about soft gripper, please contact me.