Design Challenge: Robotic Gripper

Introduction to the challenge

Prompts and questions to ask the students

  • What is a robot? Have you seen one? Seen videos?
  • Why do you think robots are made human-like?
    • Human anatomy (body) is very functional (balance, grip, etc)
  • Have you ever played a “claw” game at an arcade? Did you win? Why/why not?
    • The claw is too weak and not well-designed to hold stuff
  • How do you hold things usually? Can you grip without your thumb?
  • Opposable thumbs are an important feature of the human hand. Try not using your thumb. Does it make easy things hard?

Videos to watch before the challenge

Aim of the Challenge

Two million people in the USA are missing a limb! Prosthetic hands and arms give them a way to keep doing the activities they love. As a bioengineer, you get to learn how to make one! Follow the steps in the Downloads section of this page to build your own bionic gripper. Test how well it works, picking up marshmallows or objects of your choice. Once you have the basic model working, design improvements to make it even better.


  • Cardstock
  • Paper towel roll (the inside)
  • String
  • Straws
  • Tape
  • Scissors
  • Marshmallows (or anything you want to pick up)


  • How many strips of cardstock should you use? How long or short can you make the cardstock? How wide or thin can you make the cardstock?
  • How does the length of the straw affect the gripper? How does the spacing of the straws affect the gripping action?
  • Should you add more straws or less?
  • Can you reinforce the cardstock with anything?
  • What other applications can this “robot hand” have?
  • What other kinds of mechanisms can you think of building that can replicate the human body parts?
    • What would their functional requirement be? E.g.: foot/leg: balance, strength etc.


Previous Work

Friday Showcase Zoom Recording

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