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TomKat Center for Sustainable Energy is joining Stanford Doerr School of Sustainability Sept. 1, 2022!

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Smart Glass

Stanford grads design better windows for smarter buildings.
Cropped Photo: Muhammad Taslim Mohd Razin

Imagine you work on the 35th floor of a downtown high-rise; you have a corner office with big glass windows overlooking the city. The sunlight and views are part of why you took the job, and it’s perfect—until 3 p.m. when the sun glares right into your eyes.

It’s a catch-22 of modern architecture. Building designers are incorporating more glass into buildings for its aesthetic beauty and daylighting. But with the better views comes a decrease in insulation that can leave occupants feeling overheated or squinting into the light. Costly additions such as triple-pane glass, reflective coatings, blinds, shades, or large chillers can solve the problem, but two Stanford grads saw room for improvement.

Through a grant from the TomKat Center for Sustainable Energy, Toby Sachs-Quintana, PhD ’14 and David Abram, PhD ’15, are developing a technology that can change the tint of windows with the switch of a button—or the flick of a smartphone.

This technology, called electrochromic glass, is on the market now, but at a prohibitively expensive price. The duo is developing a better production technique to bring “smart” glass to the mainstream.

Electrochromic windows have the ability to tint in response to an electric pulse. They darken or lighten depending on the voltage sent across them, allowing users to dynamically block sunlight without any blinds. The windows are currently manufactured through a process similar to that used for silicon computer chips, depositing thin layer upon thin layer of a coating onto the glass.

NexTint, as Sachs-Quintana and Abram have named their venture, is exploring a faster and less expensive manufacturing process. By iterating with a wider variety of electrochromic materials that can be applied more simply, the NexTint founders hope to lower costs and also provide more color choices. (Most smart windows now use tungsten oxide, a metal-oxide coating that transitions to what industry critics endearingly call “Smurf blue.”)

The two scientist-entrepreneurs also hope to design a window insert that can quickly retrofit existing buildings, rather than design a flat glass product, which can only be used in new construction. The concept could have applications in other markets as well, such as sunglasses and automotives.

If the technology comes to fruition, the environmental impacts could be enormous. Buildings use 71 percent of the electricity consumed in the United States, with nearly a third of that energy due to what is lost through windows .  If NexTint’s window film was broadly applied throughout the United States, the amount of electricity that could be saved in a year is enough to power Australia for six years.

So far they have demonstrated a 10-year lifetime of their emerging technology using a device that accelerates normal wear and tear on the windows; they started with a 2-inch-by-2-inch window sample and have worked up to one that is 1 foot by 1 foot. Next they plan to test a full-sized window, at which point they will begin pilot installations with local companies.

Although Sachs-Quintana and Abram were pursuing doctorates in different fields (materials science and chemical engineering, respectively), they knew each other through mutual friends. After bumping into one another at a Stanford event for budding entrepreneurs in 2014, they decided to team up. Sachs-Quintana, the company CEO, knew how to stabilize organic materials from his previous work with photovoltaic panels. Abram, the CTO, had the electrochemistry expertise.

They applied for several grants at once to jumpstart the idea, including the National Science Foundation (NSF). But only the TomKat Center was willing to take the risk initially. After completing the terms of their TomKat grant and showing the initial promise of the technology, NSF decided to award NexTint funding, as did private investors.

Since then, NexTint went on to win $35,000 at the MIT Clean Energy Prize and $15,000 at the U.S. Department of Energy FLOW business plan competition. This summer, the team has grown to include Hazem Elhagrasey, a Stanford Business School Sloan Fellow and Eric Davey, a Stanford engineering graduate student.

With their doctorates now complete, Sachs-Quintana and Abram are working full time on NexTint, which they call a dream job.

“The TomKat grant was really the catalyst,” says Sachs-Quintana.

Adds Abram: “We definitely wouldn’t be here without it."

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Top Photo: Muhammad Taslim Mohd Razin