Smart Curtains for Spontaneous Solar Modulation via Natural Light-Triggered Deformable Shading and Chromogenic...

Area of Science:

• Materials Science
• Sustainable Building Technologies
• Nanotechnology

Background:

• Smart windows offer tunable transparency for thermal management but suffer from overcooling and instability due to solid-state chromogenic material properties.
• Existing smart window technologies often require costly window replacement and struggle with precise solar modulation.

Purpose of the Study:

• To develop flexible smart curtains using stimulus-responsive chromogenic nanowires and photothermal actuators for improved solar modulation and temperature control.
• To demonstrate a novel approach for enhancing indoor comfort and energy efficiency in buildings without replacing existing windows.

Main Methods:

• Integration of stimulus-responsive chromogenic nanowires (thermochromic or photochromic) with photothermal actuators based on differential thermal expansion of bacterial cellulose and polyethylene.
• Fabrication of macro-deformed smart curtains that exhibit reversible curling and unrolling behavior in response to varying light intensities.
• Characterization of solar radiation modulation, temperature reduction capabilities, and off-state solar transmittance.

Main Results:

• The smart curtains achieve temperature reductions exceeding 6.0°C by regulating solar radiation, with 62.3% reduction for thermochromic and 79.1% for photochromic versions.
• In the off-state (low light), the curtains allow 92.0% solar radiation transmission, facilitating passive heating.
• The smart curtains demonstrate a light-intensity-dependent deformation (curling/unrolling) for dynamic solar modulation.

Conclusions:

• The developed smart curtains offer a feasible and effective solution for dynamic solar modulation and indoor temperature regulation.
• This technology represents a significant advancement in sustainable building design, providing energy savings and enhanced occupant comfort.
• The direct-mount capability of these smart curtains bypasses the need for window replacement, simplifying implementation in existing structures.