A Novel SESC Microstructure to Realize Various Spontaneously Liquid Spreading Properties

We report design and fabrication of a novel microstructure with both sharp edge and sharp corner (SESC) in its topography, which can be tailored to achieve various liquid spreading properties. The sharp edge of the SESC microstructure can hinder liquid spreading in one direction, while the sharp corner can enhance liquid spreading in another direction. By utilizing the two opposite effects of the sharp edge and the sharp corner, two different types of anisotropic wetting properties are demonstrated, including bidirectional water spreading on a 2-D SESC microstructure and unidirectional water spreading on a 3-D SESC microstructure. On the fabricated 2-D SESC microstructure, contact angle difference in parallel and perpendicular direction can reach 93.8°, which is the highest in published works.