Reflect on a world where controlling the brightness and heat entering our homes and offices is as simple as pressing a button. This is the promise of dynamic windows, an exciting realm where technology meets daily living. Dynamic windows based on reversible metal electrodeposition are emerging as a promising solution due to their color neutrality, cost-effectiveness, and dynamic range. These windows operate by electrochemically depositing metal ions onto a transparent surface, thereby adjusting light transmission. This process, when precisely controlled, can transform windows from transparent to opaque, offering privacy and energy efficiency in one seamless package.
The University of Colorado Boulder team, led by Professor Michael McGehee, has now taken this technology a step further. In their study published in Cell Reports Physical Science, they explored pulsed electrodeposition, a method that marks a significant departure from the conventional direct current (DC) electrodeposition. The traditional approach, while effective, often results in uneven film surfaces, hindering the windows’ ability to rapidly switch between states.
“Pulsing allows us to create smoother films. This is critical as it not only enhances the speed at which windows transition to a privacy state but also significantly increases the life span of these windows,” explained Professor McGehee, emphasizing a key breakthrough.
The study shows that pulsing, though initially slower in tinting compared to DC plating, achieves a near-total opaque state more quickly. This improvement is credited to the reduced growth of dendrites, common issues in metal electrodeposition, leading to smoother and more uniform films.
Another notable advancement is the durability of these dynamic windows. Using a pulsed voltage cycling method, the research demonstrated that the windows retain their optical qualities consistently even after thousands of use cycles, representing a considerable advancement over previous iterations. The pulsing technique considerably mitigates dendrite growth on the metal mesh counter electrode, a crucial aspect in prolonging the window’s life.
“Our findings represent a significant step forward in dynamic window technology,” noted Professor McGehee. “We not only achieve quicker transitions between tinting and clearing but also ensure a prolonged lifespan for these windows, making them more viable and cost-effective for broad application.”
In summary, the pulsed electrodeposition method marks a major milestone in the field of dynamic window technology. By guaranteeing faster transitions, smoother film morphology, and extended durability, this method promises to boost the energy efficiency of buildings while providing an enhanced user experience and aesthetic appeal.
Andrew L. Yeang, Ziliang Li, et al., “Pulsed electrodeposition for dynamic windows based on reversible metal electrodeposition,” Cell Reports Physical Science, November 2023. DOI: https://doi.org/10.1016/j.xcrp.2023.101660