These ultra -thin flexible solar panels are so light that you can wear them

While the summer temperatures in Osaka, Japan, closer to 100 degrees Fahrenheit, the staff of Expo 2025 are looking for the heat with aunts driven by the sun.

Developed by Toyota Group Company Toyoda Gosei, in collaboration with Solar Cell Startup Enecoat technologies and textile manufacturer Seiren, the Utility vests are equipped with Ultradunne, flexible solar panels, each with less than four grams of roads-lighter to keep the Wearer Nek-Fans to keep the Nek-Fans to keep the Nek-Fans to keep the Nek-Fans Fans Fans-Fans.

These “films” on solar energy are not like the silicon panels that are installed on roofs or solar farms, which today represent 98% of the market for solar energy. Instead, they are made from Perovskites, a family of crystals that share the same characteristic structure.

Perovskiet solar cells are lighter, cheaper to produce and can be coordinated to absorb a wider light range, including visible and near infrared. They can even be charged “under the shade, in rainy and cloudy weather,” says Shinichiro Fuki, director of the Toyoda Gosei team behind the vest.

In the Laboratory, the Enecoat solar film has achieved 21.2% efficiency, which means that about one fifth of the solar energy is converted into electricity. Now it is being tested in real-world circumstances at the expo.

The team collects daily data on how it responds to different climate conditions, such as solar radiation and temperature, as well as the performance of the mobile battery with which it connects, which is expected to fully charge within five to 10 hours.

According to Fuki, the project is a “World-first Initiative” to integrate perovskite solar cells in wearables. “We hope that people who work in an environment where they cannot easily gain strength will use and wear it without solar energy,” he adds.

Low light zones

Perovskites can be found in nature or made in a laboratory, and their use in solar cells was first demonstrated in 2009 by researchers in Japan.

In lab institutions, perovskites have achieved the efficiency of electricity conversion of more than 26%uncertain the same as the best-performing silicon solar panels today, which have almost reached their efficiency limits.

One of the biggest advantages of perovskites is their ability to “generate electricity indoors or in low light environments,” says Tamotsu Horiuchi, director and chief technology officer at Enecoat Technologies.

“When indoors, instead of sunlight, the light of LEDs, fluorescent lamps or similar lights will be used to produce strength,” says Horiuchi. And because they are more flexible and lighter than silicon panels, “we can install solar panels, even in places where it was previously impossible,” he adds – such as roofs that cannot support silicon solar panels that can weigh up to around 50 pounds (23 kilograms).

The vests are not the only demonstration of perovskites on the Expo: Polish company Saule Technologies has used bent solar cells in “Smart Poles” that charge Power Street Lights, security cameras, digital signage and wireless, and the Japanese company Sekisui Chemical demonstrates its one-Millimeter.

In the Panasonic Group pavilion, perovskiet soles that are sandwiched between glass layers to offer extra durability converted into an artistic facade to show the aesthetic potential of the technology.

“The current (silicone) solar panels are difficult to install in our living space,” says Yoshiteru Hara, technical director of the Panasonic Pavilion at Expo 2025 Osaka. “We have to make a balance between design and efficiency of power generation.”

Powerful, short duration

Japan invests heavily in perovskiet technology to achieve ambitious goals to generate 20 Gigawatt Zonne energy by 2040, the equivalent power produced by approximately typical 20 nuclear power plants. The nation is the world’s second largest producer of iodine, an important ingredient in perovskites, and the mountainous terrain of the country limits the potential development of traditional solar farms, which require huge amounts of flat land.

Despite the benefits, Perovskites relegate faster than silicon when exposing to heat, moisture or UV rays, which means that efficiency loses efficiency in a few years or even weeks.

“Everyone is now working on stability: that is the only thing that perovskites miss and still have compared to silicon,” says Dr. Hashini Perera, a postdoctoral researcher at the Advanced Technology Institute of the University of Surrey, where she studies Perovskites.

Researchers are investigating different ways to make perovskites more sustainable, such as adding “stabilizing agents” or dealing with the film in protective layers, such as glass, says Perera, whose recent research discovered a method that could increase the lifetime of the material ten times.

Another challenge of perovskites is that they contain lead, which is toxic. Studies have shown that this can cause an environmental risk as damaged, but Perera says that the potential for lead leakage is very low, especially with robust encapsulation methods.

Although solar cells that Just Perovskite use, still have a long way to commercialization, it is already improving existing panels: Last year, Oxford PV, a company that was spun from the University of Oxford, deliver the first commercial perovskiet-on-Silicon Tandemonic in the US in the US cell.

“It’s a huge step forward for Perovskites,” says Perera.

The ability of Perovskite to bring energy generation to urban areas, closer to where it is used, will also make future cities more efficient, says Horiuchi, Chief Technology Officer at Enecoat.

“It is more effective to use the electricity that has been generated there (on the spot) to power the building itself,” says Horiuchi, adding: “The same applies to clothing. I think the best way to use it is … on a smartwatch or your smartphone. I think it would be good to develop it that way.”

Additional reporting by Yumi Asada, CNN.

For more CNN news and newsletters create an account on CNN.com