Capillary force
= Capillary force
A <force> caused by an interface through its contact-line <surface tension> and the <capillary pressure> it produces. Both contributions must be counted with consistent geometry. For a narrow, completely <wetting> <liquid> bridge between flat plates of wetted radius $a$ and gap $d\ll a$, the leading attractive <force> is $2\pi a^2\gamma/d$.