Critical Casimir Effect — Thermal Fluctuation Force

t = (T-Tc)/Tc: 0.00 Plate separation L/a: 8 Animate ξ

Near the critical point (t→0), thermal fluctuations in a confined fluid generate a critical Casimir force F ~ −kT·Δ(L/ξ)/L³. The force is attractive for symmetric boundary conditions and strongest when ξ~L.