Make robot fingers, talons or claws

What can we use instead of plastic straws if we can't find any?

If you don't have plastic straws, roll and tape strips of paper into tight tubes and tape them onto the long taped side of each cardboard joint so the string can still slide through as described in the instructions.

The finger won't curl smoothly — what should we check or change?

If the finger doesn't curl, try replacing thick yarn with thinner thread or dental floss, loosen or reposition the tape holding each straw to the taped joint so the straw openings align, and retest the bending at each taped joint.

How can I adapt this activity for younger children or make it more challenging for older kids?

For younger children, pre-cut the three same-size cardboard rectangles and pre-thread the straw pieces so they only tape the finger to the palm and pull the string, while older kids can add extra fingers, build a multi-finger hand, or use hot glue (with supervision) instead of tape to make sturdier joints.

What are simple ways to personalize or improve the robot finger after finishing it?

You can personalize the palm and cardboard segments with markers or paint, attach additional taped fingers using the same straw-and-string method to make a multi-finger gripper, or secure the loose string under a small homemade lever on the palm (using the tape tab) to create a better control mechanism.