Bioinspired Novel Anti-Fog Coatings

Many optical systems can be temporarily disabled due to fogging of the surface. While coatings and treatments exist to prevent fogging, they are either temporary or have intrinsic drawbacks. For example, traditional additive-based anti-fog coatings have a slow response time and suffer from a continuous loss of the additives during the product lifetime. Superhydrophilic anti-fog coatings developed recently can maintain optical transparency during condensation, but under high humid environments the excess amount of water accumulated on the surface can be problematic. Hydrophobic coatings, such as superhydrophobic coatings can repel large water droplets but can not prevent tiny water droplet attachment during fog condensation, which can cause light scattering and appear opaque. PSI proposes a bioinspired novel anti-fog solution that can avoid the disadvantages of the currently available anti-fog methods while retaining their advantages. When used on optical systems, the proposed coatings can maintain high optical transparency during condensation and at the same time be water-repellent. During Phase I, we will demonstrate a scalable and low-cost fabrication process to produce the proposed anti-fog coatings on optical components. The proposed coating will be permanent, salt-tolerant and is expected to surpass the performance of current anti-fog coatings or treatments.