1. Do Now
Smartphones have large glass screens that respond when you touch them.
How do you think the phone "knows" where you are touching it? Write down your ideas in your lab notebook.
Image from Gigaohm.com

2. Image from electronics.howstuffworks.com

3. Cutaway view of touchscreen
Yoo et al. (2008), Solar Energy Materials & Solar Cells 92(8):

4. Sol-Gel Spin Coating Drip Spin Spread Dry
Image from commons.wikimedia.org
Drip
Spin
Spread
Dry
Making thin-film electronics requires a solution that will spread and dry evenly on the SUBSTRATE (surface material) you’re spreading it on.

5. Intermolecular forces pull molecules together
Image from chemizzle.com

6. Intermolecular forces create COHESION and ADHESION
Images from

7. Water on mirror: ADHESION > COHESION COHESION > ADHESION
Water on soap:
COHESION > ADHESION

8. Contact angle shows the balance of cohesion & adhesion
Angle is measured from one side of the drop to the other. (Drop should be inside the angle)
Images from

10. VERY POLAR, SOMEWHAT POLAR, OR NONPOLAR?
acetone
ammonia
VERY POLAR, SOMEWHAT POLAR, OR NONPOLAR?
water
chloromethane
2-methylpentane
commons.wikimedia.org