Figure 2

(a) Laser scanning confocal image of a gas capillary between the particle and superamphiphobic surface captured during retraction in water and (b) illustration of a catenary shape gas capillary between a spherical particle (radius R) and a flat surface at separation D, with the diameter of the de-wetted area on the flat surface (d_c), the angle defining the de-wetted area on the particle (β) and the microscopic contact angles at the gas–liquid interface of the flat surface (θ_s) and particle (θ_p).