posted on 2023-12-07, 03:29authored byHao Cao, Hongfeng Deng, Hui Wan, Shiyi Luan, Su Shen, Chengqun Gui
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.