I thought of it after I saw this Simple Animatronics
Step 1: Materials
1/2 in pipe
nails, or thin metal dowel
thin steel cable
Step 2: Measuring and cutting
Cut the pipe to the measured lengths. You should have 19.
Cut the ends 45 degrees, except for the fingertips and the wrist.
Step 3: Hinges
Step 4: Cutting
Step 5: Finger welding
Weld the nails beside the joint to prevent the finger from bending backward. weld it onto the lower segment, not the top, because it looks cooler. if you have 24 weld it on both sides of the joint.
weld a nut at the end of each fingertip.
Step 6: Finger alignment and more welding
Position the fingers correctly on the palm and weld them there.
Cut the rest of the plate to be the palm from the thumb to the pointer finger.
Position the thumb on the plate and weld it there.
Weld the thumb palm to the finger palm. (if you think it will work, you could try welding a hinge in there so it could grasp better.)
Step 7: Arm
Cut the pipes where they reach your bicep when your fingers are touching the wrist.
Make double sided duct tape arm straps (sticky on the inside)