The Claw – Bay Area Discovery Museum

The Claw

Test the ability of various robotic arms for complete a range of tasks, then design and build your own.

Materials Required

  • Grabbers (various types, e.g. trash pickers, tongs, chopsticks)
  • Clothes hamper
  • Clothes from the lost and found, hamper, or closet
  • Toy chest or other container of a similar size
  • Variety of toys
  • Garbage can filled with clean “trash,” such as empty yogurt containers, plastic bottles, lids, etc.
  • Materials for building end effector prototypes:
    • popsicle sticks
    • straws
    • rubber bands
    • tape
    • pipe cleaners
    • cardboard tubes
    • wire coat hangers
    • dowels
    • bamboo skewers
    • wooden paint stir sticks
    • double stick tape
    • Velcro


  1. Invite children to use the gathered grabbers to perform household tasks such as picking up clothes and toys and sorting trash.
  2. Introduce children to the robotics term end effectors, which refers to the robotic arm, or the part of the robot where the arm and hand fits and is able to perform tasks.
  3. Encourage children to use the information gathered from the previously performed tasks to find inspiration for their own project, using materials like straws, popsicle sticks and paint stirrers to build their own end effector.
  4. Have children test their own creation by using it to pick up clothes and toys or sort trash.
  5. Let children refine and improve their design, then test it again.
  6. If they’d like, children can name their end effector based on what it does.

Additional Tips

Try these add-on activities:

  • Look at images or watch videos online of various types of real robotic end effectors. Point out the different types of grippers and tools at the end of the robotic arms and discuss how their design enables their performance.
  • Challenge children to modify their grabbers to do an additional challenge such as reach an object 5 feet away without dropping it, or pull down the cookie jar from a high shelf and open the jar.

Links to Creativity

Being faced with limitations can help spark creativity. How one responds to limitations and constraints says a lot about the flexibility of one’s thinking (Stokes, 2001, 2005), which through practice can indeed be improved. With some cognitive flexibility, a list of seemingly mundane items can be transformed into functioning robotic arms. For this activity, children expand their creativity by: (1) generating novel uses for ordinary items (see divergent thinking; Guilford, 1949); (2) allowing their thoughts and actions to be embodied when using these robotic limbs (i.e., embodied cognition; Varela, Thompson, & Rosch, 1991); and (3) solving problems that were once unimaginable (Torrance, 1978).

Supporting research includes:

Stokes, P. D. (2001). Variability, constraints, and creativity: Shedding light on Claude Monet. American Psychologist, 56(4), 355-359.

Stokes, P. D. (2005). Creativity from constraints: The psychology of breakthrough. New York: Springer Publishing Company.

Torrance, E. (1978). Giftedness in solving future problems. The Journal of Creative Behavior, 12(2), 75-86.

Varela,  F.  J.,  Thompson,  E.,  &  Rosch,  E.  (1991).  The  embodied  mind: Cognitive science and human experience. Cambridge, MA: MIT Press.


This activity was contributed by the Bay Area Discovery Museum. ©2017 Bay Area Discovery Museum. For more information and resources see

The Claw

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