The video below explores what causes your fingers to wrinkle after a long soak in the tub and suggests that wrinkly fingers might improve our ability to handle wet objects. Test this hypothesis in the following experiment, which uses only a water bottle, a paperclip, and a plastic ruler.
Target Grades: Grades 6-8
, Engineering and Technology
“Getting a Grip on Finger Wrinkles,” produced by Flora Lichtman
Smooth, plastic ruler with a hole at one end (without raised lines or numbers)
Large paperclip, straightened out
Large water bottle with screw cap, with a looped lid for paperclip attachment
Notebook or student data sheet
Bowl of water for soaking fingers
Water may splash in this experiment. Always walk—never run—in the laboratory, and steer clear of electrical equipment and outlets while conducting this experiment.