Cost-Effective Smart Window: Transparency Modulation via Surface Contact Angle Controlled Mist Formation

Implementing simple and inexpensive energy-saving smart technologies in households is quite effective to accomplish on-demand privacy control and reduction in energy consumption. Conventional smart glasses face difficulty in making inroads into the consumer market due to utilizing expensive active layers, electrolytes, and transparent electrodes. Thus, the need of the hour is to develop an unconventional smart window, which should be cost-effective, power-efficient, and simple to fabricate. Against this backdrop, we report the fabrication of a new class of smart partition windows termed mist-driven transparency switching glass. The fabrication protocol includes surface energy modification of two glass panes, followed by assembling them into a square or rectangular-shaped narrow cell with appropriate inlets and outlets for mist. In its pristine state, the device is transparent, as expected of two plain glasses forming a cell. Insertion of cool mist into the device produces tiny droplets onto the inner walls due to condensation enabling scattering of light, thereby producing the translucent state. The optimized device shows a transmittance modulation of as much as similar to 65% at 550 nm, allowing it to reduce the indoor temperature by more than 30% compared to a regular glass windowpane. To realize commercial viability, a large area device (30 x 30 cm2) was fabricated, which could be operated wirelessly through a cellphone application paving the way for incorporating the Internet of Things into the technology.

Automated summary

Implementing simple and inexpensive energy-saving smart technologies in households can effectively achieve on-demand privacy control and reduce energy consumption. To meet the demand of the consumer market, an unconventional smart window that is cost-effective, power-efficient, and simple to fabricate is needed. A mist-driven transparency switching glass was developed, showing significant temperature reduction and the ability to be operated wirelessly through a cellphone application, making it commercially viable and suitable for IoT integration.