About the author: Janna Rathert recently completed a Ph.D. in Mechanical Engineering under the direction of Prof. Jason Valentine at Vanderbilt University and Prof. Cary Pint at Iowa State University. The collaboration between the Pint and Valentine groups seeks to explore ways in which electrochemical methods can be leveraged to reversibly modulate photonic devices, especially metamaterials. Janna’s recent publication shows that the electrochemical lithiation of anatase titanium dioxide results in a substantial change in refractive index throughout the visible spectrum, making this material well-suited for dynamic visible color tuning. The dynamic range, speed, and cyclability of TiO2-based metasurfaces indicate that this system is competitive with established actuators like WO3, with the additional advantage of reduced absorption at high frequencies.