A solar/radiative cooling dual-regulation smart window based on shape-morphing kirigami structures

Area of Science:

• Materials Science
• Building Physics
• Sustainable Energy

Background:

• Buildings account for significant global energy consumption, with windows being a major source of inefficiency.
• Conventional smart windows primarily control solar transmittance, neglecting radiative cooling, and existing dual-control solutions have durability and performance limitations.

Purpose of the Study:

• To develop a novel dual-control smart window that simultaneously manages solar transmittance and radiative cooling.
• To overcome the limitations of existing smart window technologies, focusing on enhanced durability and energy-saving performance.

Main Methods:

• Proposed a smart window design integrating a reconfigurable kirigami structure with a polydimethylsiloxane-laminated thermochromic hydrogel coated with silver nanowires.
• The design utilizes the thermochromic hydrogel's phase transition for solar gain control and the kirigami structure's emissivity modulation for radiative cooling.

Main Results:

• Achieved a solar transmittance modulation of approximately 24% and long-wave infrared emissivity regulation of 0.5.
• Demonstrated significantly improved durability, with a lifespan nine times longer than conventional smart hydrogels.
• The design effectively suppresses solar heat gain in summer and heat radiation in winter.

Conclusions:

• The novel dual-control smart window offers a promising solution for energy-efficient and durable building envelopes.
• This approach outperforms existing state-of-the-art smart windows in dual solar/radiative cooling regulation.
• The integrated kirigami and hydrogel system provides a robust and effective method for dynamic thermal management in buildings.