Break the Tension
Students learn about and experiment with the concept of surface tension. How can a paper clip "float" on top of water? How can a paper boat be powered by soap in water? How do water striders "walk" on top of water? Why do engineers care about surface tension? Students answer these questions as they investigate surface tension and surfactants.
How can a paperclip "float" on top of water?
Environmental, chemical and civil engineers are all interested in surface tension and surfactants. They study the interactions between surface tension and chemicals as they develop technologies to remove pollutants from our water and air resources. Surface tension also affects many construction materials, so civil engineers consider the surface tension of water when incorporating wooden beams into a building's design. Using water to attach two materials is often convenient, non-corrosive, readily available, transparent, and is easily undone. Engineers also develop technologies for people that are inspired by designs in nature (biomimicry), such as insects that rely on surface tension for survival.
After this activity, students should be able to:
- Define and describe surface tension.
- Define and describe a surfactant.
- Describe some uses of surface tension and surfactants by engineers.