Scalable method of fabricating structured polymers for passive daytime radiative cooling and other applications
US11940616B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 2018 |
| Grant date | Mar 26, 2024 |
| Priority date | — |
| Expiry date | Feb 19, 2040 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE06B2009/2417
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A switchable light transmission module is disclosed that includes a substrate having a first surface defining at least part of an enclosed volume, a porous layer disposed on the first surface and in fluid communication with the enclosed volume, and a reservoir in fluid communication with the enclosed volume. The reservoir is configured to supply a fluid to the sealed volume such that the fluid contacts the porous layer. The fluid has a refractive index that is close to the refractive index of the porous layer, has a high wettability for the porous layer, and does not dissolve the porous layer. When in a dry state, voids in the porous layer are filled with air which has a much different refractive index than the porous layer itself, resulting in a surface that is reflective and not very transmissive. During wetting of the porous layer by the fluid, however, those voids are filled with the fluid, reducing the difference in refractive index across the polymer-fluid interfaces such that light scattering is negligible and the surface becomes light permeable.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.