Indian researchers at the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, have developed a new class of smart windows that not only regulate light and heat but also function as energy storage devices. This innovation promises to make smart window technology more affordable and accessible, especially in energy-conscious and climate-sensitive regions.
Traditionally, smart windows rely on expensive materials like tungsten oxide and lithium-based electrolytes to control light and temperature. However, the Bengaluru team, operating under the Department of Science and Technology (DST), India, has shifted to cost-effective alternatives—using titanium dioxide (TiO©ü) films and aluminium-ion electrolytes.
These smart windows, with film thickness as low as 340 nanometers, demonstrate remarkable performance. They achieve modulation levels of 55% for solar light, 47% for visible light, and 41% for near-infrared radiation. Moreover, they retain 96% of their capacity even after 2,000 switching cycles, highlighting their durability and efficiency.
Beyond modulating light and heat, the windows also store energy like capacitors, offering nighttime privacy with a dark-blue tint and enough stored power to run small electronic devices. This dual functionality positions the innovation as a potential game-changer for smart, energy-efficient buildings.
¡°This development can reduce the energy demands of buildings significantly by limiting heat intake during summers and conserving indoor warmth in winters,¡± said a CeNS spokesperson. ¡°Its cost-effectiveness also means wider adoption, especially in resource-limited settings.¡±
This is not the first time CeNS researchers have made strides in smart materials. In 2023 and 2024, they experimented with polymeric electrochromic devices and transparent aqueous batteries. This latest breakthrough represents a culmination of their work, delivering a solution that combines affordability, scalability, and performance.
Experts believe that with further optimization, these smart windows could play a pivotal role in advancing net-zero energy buildings across India and beyond.