Superrepellent Doubly Reentrant Geometry Promotes Antibiofouling and Prevention of Coronavirus Contamination

Abstract

The fomite transmission of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has drawn attention because of its highly contagious nature. Therefore, surfaces that can prevent coronavirus contamination are an urgent and unmet need during the coronavirus disease 2019 (COVID‐19) pandemic. Conventional surfaces are usually based on superhydrophobic or antiviral coatings. However, these coatings may be dysfunctional because of biofouling, which is the undesired adhesion of biomolecules. A superhydrophobic surface independent of the material content and coating agents may serve the purpose of antibiofouling and preventing viral transmission. Doubly reentrant topology (DRT) is a unique structure that can meet the need. This study demonstrates that the DRT surfaces possess a striking antibiofouling effect that can prevent viral contamination. This effect still exists even if the DRT surface is made of a hydrophilic material such as silicon oxide and copper. To the best of our knowledge, this work first demonstrates that fomite transmission of viruses may be prevented by minimizing the contact area between pathogens and surfaces even made of hydrophilic materials. Furthermore, the DRT geometry per se features excellent antibiofouling ability, which may shed light on the applications of pathogen elimination in alleviating the COVID‐19 pandemic.

Nature-Inspired Surface Structures Design for Antimicrobial Applications

“…The superhydrophobic surfaces that do not require the coating of additional materials for antimicrobial purposes have significant potential for industrial applications owing to their long service lives and lower structural limitations (owing to the absence of a coating). A notable example is the double reentrant topology (DRT) surfaces that possess anti-biofouling properties and antibacterial adhesion effects (Lee et al, 2022) [ 155 ]. A DRT is a structure with a negative sidewall angle, such as in mushrooms or umbrellas ( Figure 4 b).…”

“…Unlike other superhydrophobic surfaces, DRT does not require the use of low-surface-energy materials to achieve superhydrophobicity, relying on its special structure [ 156 ]. In a study by Lee et al (2022), DRT surfaces were observed to remain superhydrophobic and exhibit low microbial adhesion behaviors, even when hydrophilic and microbe adhesive materials (SiO 2 ) were used as contact materials [ 155 ]. The DRT surfaces can be considered mechanical anti-biofouling surfaces and may serve as an example that inspires the development of novel antibacterial surfaces.…”