The Next Generation of Windows Is Already Here

The window is one of those design objects so familiar we've stopped seeing it as a design object at all. A hole in a wall, more or less. We've refined it—glazed it, doubled it, screened it, tinted it—but the basic proposition hasn't changed in millennia: cut an opening, fill it with something transparent, try not to lose too much heat in the process.

That last part is where things get genuinely interesting right now. Buildings account for roughly 40% of global energy consumption, and a significant chunk of that is HVAC systems fighting what comes through windows. The glass that lets in light also lets in heat. The same pane that brightens a room in January is running your air conditioner ragged in July. It's an old tension, and researchers across materials science, physics, and chemistry are attacking it from five very different directions.

SciShow's Deboki Chakravarti recently walked through all five in a video published last week, and the range is striking—from incremental refinements of existing tech to prototypes that look like something out of marine biology.

The Film Problem Nobody Fixed (Until Maybe Now)

Window films have existed since at least the 1960s. The concept is simple: a thin coating on the glass that reflects heat before it enters. The execution has always had a catch.

As Chakravarti explains, "a lot of films are optimized for a 90° angle of incidence"—meaning they perform best when light hits the window perfectly perpendicular. The sun almost never does that. During the hottest parts of the day, light hits vertical windows at a sharp, low angle. The films that should be blocking heat are, at exactly those moments, operating near their worst.

A 2024 paper describes one team's approach to fixing this: a multilayer film where each layer has a distinct refractive index (the degree to which it bends light passing through). The stack was engineered using quantum computer-assisted modeling, tuning how light bounced across a range of angles rather than optimizing for one. Tested on vertical windows outdoors, it reduced temperatures on the other side of the glass by up to 5.4°C—measured against uncoated glass, not existing commercial film. That benchmark matters. It's a clean result, but it also means the comparison to what you'd actually replace is still an open question.

A Patent From 1913, Finally Ready for Its Moment

Vacuum-insulated windows solve the heat transfer problem more architecturally. To understand why, you need the three mechanisms through which heat moves: conduction (direct contact), convection (fluid movement, including air), and radiation (energy waves). Eliminate enough of these, and heat stops traveling through your window.

The company LuxWall has built what they call transparent insulation: two tempered glass panes separated by microscopic structural pillars—sand-grain sized—with a vacuum pulled between them. No air means no convection. The pillars are so small that conduction is negligible. To address radiation, they've added a low-emission coating. The result is a window that blocks heat transfer across all three mechanisms simultaneously.

The underlying idea, it turns out, has been around for over a century. A German patent for a "hollow glass pane" dates to 1913, and commercial vacuum windows have existed since the 1990s. The problem was always cost and longevity—the vacuum degraded too quickly to justify the price. LuxWall's advance is primarily manufacturing and materials: innovations in ceramics, physics, and automation have made the product durable and economically viable for a broader range of buyers.

That's worth sitting with. This isn't a new idea having a breakthrough moment. It's an old idea finally having its production moment. The science was settled a century ago; the barrier was industrial.

Wood, Eggs, and a Question About What "Transparent" Means

If the first two technologies are about managing what glass does, the transparent wood research is about replacing glass entirely. Wood is roughly 25 times better at trapping heat than glass—an enormous thermal advantage—so the appeal of a see-through wooden window is obvious on paper.

The challenge is that what makes wood brown and opaque is lignin, a structural polymer that needs to be removed or neutralized. Strip it out chemically and fill the remaining cellulose skeleton with something clear, and you get a material that transmits light.

A team from Kennesaw State University published work in 2025 on an eco-friendly version of this: they stripped balsa wood with sodium sulfite, then filled the skeletal structure with a mixture of rice extract and egg whites—a combination reportedly inspired by ancient Indian building traditions that used egg whites as a binding material. The result is semi-transparent and brownish. Not a window you'd put in a showroom yet.

A parallel project working with bamboo (technically a grass, but chemically similar enough to wood to belong in this conversation) took a different approach: rather than filling the stripped structure, researchers compressed it until it became a thin, flexible, translucent sheet. Think frosted glass, not crystal clear.

Neither material is ready to replace a window pane in any conventional sense. What they represent is the early-stage proof that the thermal advantage of plant-based materials might eventually be captured in a buildable form. The gap between "interesting material" and "viable product" is where most of this research still lives.

Electricity as the New Curtain

Electrochromic windows—panes that change tint when electricity is applied—are the category closest to something you might actually encounter in a building today. The concept has been around for decades; what's new is the sophistication of the mode-switching.

A 2025 paper from the Korea Advanced Institute of Science and Technology describes a three-mode system using a chemical called Prussian white and a silver-infused electrochromic gel. In the first mode: clear, like any window. In the second mode, electricity triggers a reaction that converts Prussian white to Prussian blue, reducing both visible and infrared light—the room dims and cools. In the third mode, a stronger electrical signal causes the dissolved silver to precipitate out of the gel and form a mirror layer, reflecting nearly all light and heat.

Critically, all three states are fully reversible. Kill the current, the window clears.

A separate team working with tungsten oxide and water achieved a similar three-mode system with different chemistry—blocking infrared while passing visible light, a selective filter that existing tinted glass can't manage. The tradeoff is that it's not a smooth dimmer; it's a preset mode, not a gradient.

Both approaches raise a question the video doesn't fully address: what does the energy cost of running these electrical systems look like against the energy savings from reduced climate control? The net benefit presumably holds—these are research papers, not marketing materials—but it's the number that would determine whether the technology makes sense across a variety of building types and climates.

Squids, Somehow

The most experimental entry is from a University of Toronto team, which published a prototype in 2023 inspired by the color-changing skin of cephalopods. Their window contains channels that can be filled with different liquids to change the pane's optical properties.

In their published experiment, they built a small test room, heated it to 39°C with a 100-watt bulb, then injected a fluid containing suspended carbon particles into the window channels. The particles blocked a portion of the light; the room dropped to 32°C in fifteen minutes.

The theoretical extension is layered panes, each filled with a different fluid targeting a different wavelength: one layer blocks infrared, another attenuates visible light, and so on. Right now the fluid injection is manual—a syringe, essentially. The researchers' longer-term goal is an automated system that learns a window's specific light exposure patterns over time and adjusts throughout the day without human input.

"Some innovations are ready for purchase and can continue to be improved," Chakravarti notes. "Some are still solidly in the R&D phase." The liquid window is squarely in the latter category—a demonstration of possibility, not a product. What it demonstrates, though, is something genuinely different: a window conceived not as a static material but as a dynamic system, one that behaves more like a living surface than a barrier.

The five technologies span a wide maturity range. Vacuum insulation and certain electrochromic systems are commercially available, if not yet widely adopted. The films, the plant-based materials, and the liquid-channel windows are research objects with uncertain timelines. What they share is a design premise: that a window's job isn't just to be transparent, but to be selectively, intelligently transparent—to let in what you want and exclude what you don't, ideally without you having to think about it.

Whether you find that prospect exciting or faintly unsettling—a building that manages your relationship with the outside world on your behalf—probably depends on how much you trust the systems doing the managing.

By Leo Santana