Surface and Topography

Stylus profilometer

Stylus (sharp tip) scanned across surface, height vs. position is recoded 

What can be calculated with stylus profilometer?

Roughness, waviness, etc

Data from stylus profilometer

2D and 3D - 3D can map roughness/3D surface profile like AFM

Optical profilometry

Non-contact, can get 3D rendering of image

Pros of optical profilmetry

• non-contact

• 3D modes easy to show

• Sub-nm scanning

• good for delicate samples

• User-friendly

Cons of optical profilometry

Limited by optics

Pros of Stylus Profilometry

• mostly 2D

• 1-10 nm resolution

• simple for 2D systems

Cons of stylus profilometry

• contact

• limited by tip radius

• works for opaque materials but not really transparent

• not good on delicate surfaces

Ellipsometry

Measuring the contact angle of liquid on a surface using Young’s Equation

Contact Angle

Higher surface Energy =

More wettability

As surface tension increases, surface energy …

Decreases

How can contact angles be measured?

With tilted plate method, where drop lies at an angle

This technique can be used to actually LOOK at (not measure) contact angles

ESEM