[Soft Matter] Smart design of wettability-patterned gradients on substrate-independent coated surfac
Highly adherent wettability patterns on the substrate-independent superhydrophobic surfaces of trimethoxyoctadecylsilane modified titanium dioxide (TiO2)-based coatings were prepared by using commercial photolithography. Three custom unidirectional channels with gradient wettability patterns were obtained by spatially selective wettability conversion from superhydrophobic to superhydrophilic when the coatings were exposed to ultraviolet light (∼365 nm). The movement behavior of droplets on these unidirectional channels was studied and the displacement of droplet movement was effectively controlled. Integrating the idea of gradient wettability patterns into planar microfluidic devices (microreactors), a self-driven fluid transport was achieved to realize droplet metering, merging or reaction, and rapid transport. This self-driven fluid transport with gradient wettability patterns has great potential in fabricating a new category of pump-free microfluidic systems that can be used in various conditions.
Huaping Wu,*ab Kai Zhu,a Binbin Cao,a Zheng Zhang,a Bingbing Wu,a Lihua Liang,a Guozhong Chaia and Aiping Liu*c Author affiliations * Corresponding authors a Key Laboratory of E&M (Zhejiang University of Technology), Ministry of Education & Zhejiang Province, Hangzhou 310014, China E-mail: firstname.lastname@example.org b State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024, China c Center for Optoelectronics Materials and Devices, Zhejiang Sci-Tech University, Hangzhou 310018, China E-mail: email@example.com