Determination of Contact Angle Hysteresis and Characterization of
Hydrophobic Properties of a Solid Surface
The tilting stage method is to
slowly tilt a contact angle sample
until the sessile drop on it begins
to move in the downhill direction.
At that time of “incipient motion”,
the downhill contact angle is the
advancing angle and the uphill angle
the receding contact angle. (Strictly
speaking, only droplet images immediately
before actual motion takes place
should be used for determination,
because once motion starts, the
system is no longer in thermodynamic
equilibrium).
The principal alternative to the
tilting stage method is having the
dispense needle remain embedded
in the sessile drop and pumping
in until the drop expands in base
area and pumping out until the drop
contracts in base area. The tilting
stage method has two comparative
advantages:
1)?? there is no problem of the
dispense needle distorting the drop
shape, and
2)?? both the advancing and receding
angles are obtained at the same
time, and from the very same droplet
and on the very same surface location
Furthermore, two of the most important
parameters which can be used for
characterizing the
(super-) hydrophobic or water repellent
properties of a sample surface,
contact angle hysteresis and the
droplet moving force (related to
the droplet volume and roll-off
angle), can be determined straightforward
by using a tilting stage.
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![](images/TSM_01.jpg) |
The unique sample
Tilting/Rotation Stage concept
allows determination of advancing
and receding contact angle simultaneously
as well as the roll- off angle,
and all of them in a very compact
way: either manual or motorized.
Tilting range: 0 ~ 90 degrees. |
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