Here is a soft robotic gripper that doesn’t require electronics to work. Roboticists at the University of California San Diego collaborated with BASF corporation researchers to make this robotic gripper. Here is how it works:

We designed functions so that a series of valves would allow the gripper to both grip on contact and release at the right time. It’s the first time such a gripper can both grip and release. All you have to do is turn the gripper horizontally. This triggers a change in the airflow in the valves, making the two fingers of the gripper release

explained Yichen Zhai.