A versatile metasurface enabling superwettability for self-cleaning and dynamic color response

TL;DR

This paper introduces a dielectric metasurface with switchable superhydrophilic and quasi-superhydrophobic states, enabling self-cleaning and enhanced optical responses, inspired by bioinspired surfaces, with easy repeatability and stability.

Contribution

The work presents a versatile, fabrication-efficient metasurface design that combines optical and wettability functionalities with reversible switching capabilities.

Findings

Achieved simultaneous optical and wettability functionalities.

Enabled self-cleaning dust removal through quasi-superhydrophobic state.

Demonstrated repeatable switching without optical performance degradation.

Abstract

Metasurfaces provide applications for a variety of flat elements and devices due to the ability to modulate light with subwavelength structures. The working principle meanwhile gives rise to the crucial problem and challenge to protect the metasurface from dust or clean the unavoidable contaminants during daily usage. Here, taking advantage of the intelligent bioinspired surfaces which exhibit self-cleaning properties, we show a versatile dielectric metasurface benefiting from the obtained superhydrophilic or quasi-superhydrophobic states. The design is realized by embedding the metasurface inside a large area of wettability supporting structures, which is highly efficient in fabrication, and achieves both optical and wettability functionality at the same time. The superhydrophilic state enables an enhanced optical response with water, while the quasi-superhydrophobic state imparts the fragile antennas an ability to self-clean dust contamination. Furthermore, the metasurface can be easily switched and repeated between these two wettability or functional states by appropriate treatments in a repeatable way, without degrading the optical performance. The proposed design strategy will bring new opportunities to smart metasurfaces with improved optical performance, versatility and physical stability.