<p>➀ The article introduces a dual-mode film made from nano-engineered scattering fibers derived from upcycled chip bags, designed for sustainable thermal management.</p><p>➁ The film absorbs solar energy in cold conditions and reflects it in warm ones, improving building energy efficiency.</p><p>➂ The film is constructed with a biopolymer base and silica nanoparticles, and its scalability and environmental responsibility are highlighted.</p>