60 seconds on – microgels for smart windows

Materials World magazine
1 Feb 2015

What is it? 

Hydrogels in the form of microscopic soft beads suspended in a liquid form to block solar heat when outside temperatures rise.
Who is involved?

Researchers from State Key Laboratory of Chemical Engineering, East China, East China University of Science and Technology, Shanghai Institute of Ceramics, College of Chemistry – Chemical Engineering, UC Berkeley and Shihezi University.

How does it work?

The main component of the hydrogel is a polymer, which has a low critical solution temperature. In a solvent, it is insoluble at high temperature but soluble at low temperature. The liquid is sandwiched and sealed between two glass panels, which change the optical appearance between opaque when at a low temperature and transparent at high temperatures. This will help moderate temperature within a house, reducing the need for heating or air conditioning.

What inspired the work?

The energy consumption of buildings in China accounts for about 35% of the total energy, leading researchers to study ways to reduce the amount of energy used in the country. After considering the solar spectrum, they designed several types of materials and structures for glass application. The solar modulation ability of the current research exhibits high efficiency and promise for future application in the home.

What could this replace?

Previous approaches of hydrogel technology for windows have swelled when heated, causing the window to not perform as well. However, the researchers say this liquid design has reduced swelling and cuts down 90% of solar radiation.