Exploring Forces
Try this!
1. Fill the full-size cup with water by dipping it into the
bowl. Try to pour the water back into the bowl. What
happens?
2. Now fill the miniature cup with water. Can you pour
the water back out?
What’s going on?
It’s easy to pour water out of a regular-sized cup, but not out of a miniature cup. That’s because size can
affect the way materials like water behave.
When you tip the regular cup, the force of gravity pulls the water out of the cup. When you tip the miniature
cup, gravity isn’t strong enough to overcome the natural tendency of water molecules to stick together.
How is this nano?
At the nanoscale, different physical forces and material properties dominate. If you were nano-sized, you’d
hardly notice gravity. Instead, you’d be concerned with how bumpy, shaky, and sticky the nano-landscape
is:
• Molecules have distinct shapes
• Thermal energy makes molecules vibrate
• Van der Waals forces make molecules stick together
NanoProperties
Exploring Forces
What’s different about nano?