The multi-layered window developed by the University of Toronto Engineering features grooves filled with liquids that possess different optical properties.
A team of experts at the University of Toronto Engineering in Canada has developed a “liquid window” with the potential to reduce energy costs associated with heating, cooling, and lighting, as reported by Interesting Engineering on February 4th. This innovative device achieves energy efficiency by optimizing wavelength, intensity, and light dispersion that passes through the window. The research was recently published in the journal The Proceedings of the National Academy of Sciences (PNAS).
The prototype window developed by the University of Toronto Engineering features multiple layers, each containing grooves filled with liquids that possess different optical properties. (Photo: Raphael Kay/Adrian So)
The prototype consists of flat plastic panels with grooves a few millimeters thick, which can be filled with liquid. The liquid is composed of pigments, particles, or customized molecules to control the type of light that passes through and how it is distributed.
The plastic panels can be combined into a multi-layered block, with each layer serving different functions such as controlling intensity, filtering wavelengths, or adjusting the scattering of light transmitted indoors.
This design is directly inspired by certain species of cephalopods that have skin containing specialized organ layers stacked together, including chromatophores (which control light absorption) and iridophores (which affect reflection and iridescence). These elements work together to create unique optical behaviors.
J. Alstan Jakubiec, a member of the research team, constructed detailed computer models based on measurements from the prototype. The team also developed various control algorithms to activate or deactivate each layer, allowing for responses to changing environmental conditions.
“Even with just one layer controlling near-infrared light transmission—without even touching the visible light portion of the spectrum—we have saved about 25% in annual heating, cooling, and lighting energy. If there are two layers, one for infrared and one for visible light, that figure approaches 50%. These are significant savings,” said Raphael Kay, an expert at the University of Toronto Engineering.
“We are also researching how to scale the system effectively to cover entire buildings. This will require considerable effort but can be achieved with simple, non-toxic, and low-cost materials,” noted Benjamin D. Hatton, a team member. He hopes that this new research will serve as a stepping stone for more innovative energy management methods in future buildings.
