• Gentle: The gripping mechanism uses pins that gently flex to the shape of the object, distributing the load force and dramatically reducing the likelihood of crushing fragile objects.
  
  
• Precise: Extremely precise pin movements allow the gripper to hold even very small objects.
  
  
• Secure: Novel mechanism secures pins, each with a surface locking strength of 500 psi. The locking forces do not affect the positions of the pins, so the pins retain their softly preset shape.
  
  
• Versatile: In addition to gripping, the conformal gripper can perform as a tool or as a means for end effector exchange.
  
  
• Reduces costs: The gripper’s conforming mechanism eliminates the need for special purpose end effectors to grasp objects.
  
  
• Saves time: Because it conforms to any shape, the gripper saves time by eliminating the need to change end effectors to grasp and manipulate objects.

• Robotics
  • End effectors
  • Adaptive tool holders
  • General purpose adaptive tools
    
    
• Computer numerical control (CNC) manufacturing
  • Flexible manufacturing cells
  • Adaptive fixturing for parts manufacturing/assembly
  • Adaptive end effectors

The conformal gripper was originally designed for use in NASA’s lunar robotics missions. Existing robotic technologies use various end effectors attached to robotic arms to perform specific tasks. To pick up and move objects, they use grippers. The two types of gripper technologies are friction grippers and encompassing grippers, each with drawbacks. Objects that are held with friction can twist, fall out, or be crushed—particularly a problem for small objects. Encompassing grippers, which are shaped to a specific object, allow the use of less force but can only be used for that specific object. Either type of gripper must be changed in order to perform a different task.

NASA’s new conformal gripper can revolutionize robotics by enabling any shape object to be picked up and manipulated, including tools used to perform jobs, without changing end effectors.

How it works:

This conformal gripper is composed of parallel jaws (fingers), sensors to measure the shape of the object, and a control mechanism for directing the shape and stiffness of the pins at each point of contact with the object’s surface. Each jaw has a matrix of pins. The pins are typically ¼ inch square but can be smaller or larger. The number of pins as well as their size is dependent upon the space available.

Using a super high-speed reduction epicyclical transmission, the locking mechanism within each “finger” holds the pins firmly in place until released. The locking mechanism transfers and distributes force to the pins using a press and an articulated flexure system. Force is distributed across the top row of pins and reacted on a column-by-column basis. Because each pin responds individually to the object’s shape, the motion of one pin does not affect the motion of others. Each pin in the matrix has a spring that brings it back into a predetermined position in the absence of other forces.

With each of the pins in its relaxed position, the conformal gripper fingers open and center on the object. As the gripper fingers close upon the object, the pins within each finger conform to the object’s shape. The controller then hardens that shape and locks each pin into position. Once grasped, the object cannot be pulled or twisted from the hold without extreme force or torque.  To continue work on another area of the object, the object must first be released (or set down) and then re-grasped from a different direction. The conformal gripper can also place the object in a conformal vice that allows a machine tool to work on the object. Once this is done, the conformal gripper can re-grasp the object and place it in a new position in the conformal vice, where the machine tool can work another area of the object’s surface. With this process, the entire surface of the object can be worked on by the machine tool without changing end effectors.

Why it is better:

Unlike existing grippers that apply force to hold objects with friction, the unique design of the conformal gripper enables grasping and firmly holding even fragile and irregularly shaped objects. The gripper does not rely on friction to hold an object and is not designed for a specific object. It eliminates the need for special grippers or end effectors for different jobs.

This technology is part of NASA’s Innovative Partnerships Program Office, which seeks to transfer technology into and out of NASA to benefit the space program and U.S. industry. NASA invites companies to consider licensing the Conformal Gripper (GSC-14952) for commercial applications.

For information and forms related to the technology licensing and partnering process, please visit the Licensing and Partnering page. (Link opens new browser window)

If you are interested in more information or want to pursue transfer of this technology (GSC-14952), please contact:

Innovative Partnerships Program Office
NASA Goddard Space Flight Center
E-mail: techtransfer@gsfc.nasa.gov