A team of physicists at the University of Colorado Boulder has created a transparent window material that significantly reduces heat loss, offering a potential breakthrough in building energy efficiency.
The new substance, named MOCHI, or Mesoporous Optically Clear Heat Insulator, allows light to pass through while cutting thermal transfer by more than half compared to standard windows.
Windows typically make up a small portion of a building’s exterior but are responsible for a large share of energy loss. While they cover about 8 percent of most structures, they can contribute nearly 50 percent of total heat exchange.
As modern architecture shifts toward larger glass surfaces, the need for an effective transparent window material that balances insulation and clarity has become more urgent.
Engineered structure balances clarity and insulation
MOCHI addresses that need by using a network of hollow silicone nanotubes. The material is more than 90 percent air, yet it maintains structure through a uniform framework that holds microscopic pores in place.
Researchers report that the material allows over 99 percent of visible light to pass through with minimal haze. In contrast, typical glass transmits less than 92 percent. Tests also showed that MOCHI conducts heat at less than half the rate of still air.
🏠 Scientists at @CUBoulder have developed a transparent window material that cuts energy loss by over 50%! Called MOCHI, it insulates like a wall while staying crystal clear. A game-changer for energy-efficient buildings. 🔬🌞 #GreenTech #EnergyEfficiency #MOCHI pic.twitter.com/8ckZKYLYID
— Tom Marvolo Riddle (@tom_riddle2025) December 15, 2025
Ivan Smalyukh, lead researcher and physics professor at CU Boulder, said creating a material that insulates like a wall while remaining optically clear has long been a challenge. He explained that traditional insulating materials, like aerogels or vacuum glass, either lose clarity as they thicken or remain costly and difficult to scale.
Scalable transparent window material shows real-world promise
What sets MOCHI apart is its scalability. The research team was able to produce square-meter sheets and multi-centimeter slabs without reducing performance. These slabs can fit into insulated glass units similar in thickness to common double-pane windows.
Even thin MOCHI films applied to single-pane glass improved energy performance to near double-pane levels. Infrared imaging confirmed far less heat leakage through MOCHI-filled windows.
In addition to energy savings, MOCHI enhances comfort by reducing condensation and dampening sound. Noise reduction tests showed a drop of up to 35 decibels at certain frequencies. The material is also resistant to water, fire, and environmental damage. Durability tests indicate a potential lifespan of 20 years, with five years of field testing showing no major performance loss.
Though MOCHI remains in the research phase, Smalyukh said the ingredients are relatively low-cost and the team is now focused on refining the manufacturing process.
The study was published in the journal Science.