Static water contact angle
The resting angle of a water drop on the surface.
Useful forCoatings, polymers, glass and treated surfacesSurface, Particle & Porosity
Contact Angle Measurement
Surface wettability by sessile-drop goniometry
Contact angle measurement images a small liquid drop resting on a solid to show how well the surface is wetted. It is a quick check of coatings, surface treatments, cleanliness and hydrophobicity.
1 test optionSessile-drop optical methodAngle range 0–180°Typical turnaround 3–5 working days
Contact Angle Measurement measurement principleIllustrative
01 / Overview
What is Contact Angle Measurement?
A drop of a few microlitres, usually water, is placed on the sample with a syringe. A camera records the drop's silhouette against a backlight, and software fits its outline to find the angle between the surface and the drop's edge where solid, liquid and air meet.
The angle is a sensitive measure of wettability: below 90° the surface is hydrophilic, above 90° hydrophobic, and above about 150° superhydrophobic. It responds to the outermost molecular layer, so it picks up treatments and contamination that bulk analysis misses.
02 / How it works
How it works
- 01
Sample is placed
The clean, flat sample sits on a level stage between a backlight and a camera.
- 02
Drop is dispensed
A syringe places a small drop of test liquid, typically 2–5 µL, on the surface.
- 03
Profile is imaged
The backlit drop is photographed as a silhouette, as a single image or a timed series.
- 04
Angle is fitted
Software fits the drop outline and reports the angle on each side and their mean.
03 / What it measures
What it measures
Hydrophilic or hydrophobic
Classify the surface by whether water spreads or beads up.
Useful forPlasma, corona and coating treatment checksSurface free energy
Estimated from the angles of two or more test liquids, on request.
Useful forAdhesion, printing, bonding and painting studiesSpreading and absorption over time
Track how the angle falls as a drop spreads or soaks in.
Useful forPapers, fabrics, porous and absorbent coatingsAdvancing and receding angles
Angles as the drop grows and shrinks; their gap is hysteresis. On request.
Useful forSelf-cleaning and anti-fouling surfaces04 / Test options
Choose the Contact Angle Measurement options you need
1 option · none added yet
05 / Sample requirements
Sample requirements
- Accepted forms
- Flat solids, films, coated substrates, sheets; pressed pellets for powders
- Size
- At least 10 × 10 mm of flat area; thickness under ~10 mm
- Surface
- Flat, smooth and level where the drop sits
- Quantity
- One or two pieces per sample, with the test side marked
- Clean, dry surface free of dust and fingerprints
- Mark the side to be tested
- Pack face-up so nothing touches the test surface
- Mention any test liquid other than water
- No wiping, tape or labels on the test area
- No curved, very rough or loose-powder samples without discussing first
Hazardous or air-sensitive samples: mention it in your request, and attach the MSDS if you have one.
06 / Results & turnaround
Results & turnaround
What you receive
- Contact angle per sample: left, right and mean
- Standard deviation over repeat drops
- Drop images with fitted profiles
- Surface free energy, if ordered with several liquids
- Report PDF
Turnaround & pricing
Typically 3–5 working days after samples reach the lab.
Price confirmed in your quotation, depending on user type, options and number of samples.
07 / Limitations
When Contact Angle Measurement isn't the right fit
Surface roughness or topography
Chemical composition of the surface
Surface charge of particles in liquid
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