Much like the human hand in the design of its metal housing, the internal structure of the vacuum gripper utilizes a latex balloon which is filled with ground coffee. The gripper is able to wrap its "fingers" around an object due to a vacuum that is applied, causing the fingers to contract. To release objects the vacuum is released and air is allowed back into the mechanism.
The elephant gripper is shaped just like an elephant's trunk and operates on compressed air. It also has three "fingers" at the end of the trunk shape to grip things. It has a special feature which causes it to automatically move aside if it touches a human. This is a safety feature for when it works with human beings. The hand is constructed using nylon.
Another robot gripper is made out of a material called polyamide. This robot is of simple design for picking up things like fruit. Its design is based on the fins of fish. Its fins close on objects to grip them, lift them up and place them down as necessary. The two fins are flexible bands which form a triangle when they meet. The arm uses pneumatic valves which utilize adjustable pressure so objects can be handled safely. A robot controller runs the device.
Another robot gripper uses a design based on the shape of cockroach legs. It utilizes multiple pairs of double-jointed "fingers" made out of plastic which are controlled by a motor that uses cables and pulleys. Its design enables it to react to different shapes and sizes in different ways, much as a human hand would react differently. The robotic hand is not able to pick up certain things like keys, however. It has built-in sensors managing its reactions to different objects which make it a good candidate for use in household robots in the future.