Advances in Hybrid Icing and Frosting Protection Strategies for Optics, Lens, and Photonics in Cold Environments Using Thin‐Film Acoustic Waves

Fogging, icing, or frosting on optical lenses, optics/photonics, windshields, vehicle/airplane windows, and solar panel surfaces have often shown serious safety concerns with hazardous conditions and impaired sight. Various active techniques, such as resistive heating, and passive techniques, such as icephobic treatments, are widely employed for their prevention and elimination. However, these methods are not always suitable, effective, or efficient. This review provides a comprehensive overview of the fundamentals and recent advances of transparent thin‐film surface acoustic wave (SAW) technologies on glass substrates for monitoring and prevention/elimination of fogging, frosting, and icing. Key challenges related to fogging and icing on glass substrates are discussed, along with fundamental mechanisms that establish thin‐film SAWs as optimal solution for these issues. Various types of thin‐film acoustic wave technologies are discussed, including recent wearable and flexible SAW devices integrated onto glass substrates for expanding future applications. The focus of this review is on the principles and strategies for hybrid or integrated de‐fogging/de‐icing and sensing/monitoring functions. Finally, critical issues and future outlooks for thin‐film‐based SAW technology on glass substrates in industry applications are presented.