Directional motion of water drop on ratchet-like superhydrophobic surfaces

► Ratchet-like superhydrophobic surfaces were fabricated. ► One-dimensional anisotropic wettabilities are observed on such ratchet-like surfaces. ► Directional differences of wettabilities are tailored by the ratchet-like structures. ► Low retention and ratchet-like structures are keys for the directional wettabilities.