Facile fabrication of high-density mushroom-shaped microstructures using the photo-lithographic technique

Abstract

Biomimetic mushroom-shaped microstructures could ignite applications as dry adhesives and superhydrophobic surfaces, however its facile fabrication still remains a challenge. In this work, we have proposed and demonstrated the facile fabrication of high-density mushroom-shaped microstructures using the photo-lithographic technique. The inverse "T" shaped light exposure in the photoresist directs the formation of the relief microstructure during chemical development, which serves as the mold for the bio-inspired surface. The requirement of one positive photoresist and one-step chemical development greatly simplifies the fabrication process, which also improves the reliability of the approach. The mushroom-shaped microstructures show significant superhydrophobic properties and has high contact angles (157.2˚). The liquid-repellent properties would be tailored by varying the densities of the mushroomshaped microstructures, which was further exploited for droplet transportation and fusion. The effects of fabrication conditions on the parameters of the mushroom-shaped microstructures were also investigated. This new approach enables facile and controllable fabrication of mushroom-shaped microstructures, implying the potential for practical applications.