Superhydrophobic Multifocal Microlens Array with Depth-of-Field Detection for a Humid Environment

Hao Cao; Hongfeng Deng; Hui Wan; Shiyi Luan; Su Shen; Chengqun Gui

doi:10.1021/acsomega.3c08680

Superhydrophobic Multifocal Microlens Array with Depth-of-Field Detection for a Humid Environment

ACS Omega. 2023 Dec 6;8(50):48572-48581. doi: 10.1021/acsomega.3c08680. eCollection 2023 Dec 19.

Authors

Hao Cao¹, Hongfeng Deng¹, Hui Wan², Shiyi Luan¹, Su Shen³, Chengqun Gui¹

Affiliations

¹ The Institute of Technological Sciences, Wuhan University, Wuhan 430072, China.
² School of Power and Mechanical Engineering, Hubei Key Laboratory of Electronic Manufacturing and Packaging Integration, Wuhan University, Wuhan 430072, China.
³ School of Optoelectronic Science and Engineering, Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215006, China.

Abstract

Microlens array (MLA) has been widely applied in augmented reality and optical imaging. When used in a humid environment or medical endoscopy, MLA needs to be both superhydrophobic and multifocal. However, it is not easy to achieve both superhydrophobic and multifocal function by integrating superhydrophobic and multifocal structures on the same surface by means of a simple, efficient, and precise method. In this paper, the superhydrophobic multifocal MLA with superhydrophobic properties and multifocal functions is successfully designed for preparation based on a method of 3D lithography and soft lithography. The 3D lithography can further help the preparation of a multifocal MLA with varying apertures and a multistep superhydrophobic structure with a round dome. The superhydrophobic multifocal MLA with periods 50 and 120 μm has perfect superhydrophobic property. The water droplet can slide and bounce off the surface at a roll angle of less than 12.9° with both multifocal and integrated imaging function, as well as up to 397 μm depth-of-field (DOF) detection range; this greatly exceeds the conventional MLA. The perfect superhydrophobic and optical property can be achieved in an extremely humid environment. The superhydrophobic multifocal MLA proposed in this paper has a promising prospect for actual practices.