Doris Kim Sung believes that too much energy and effort is spent cooling buildings. In the twentieth century home construction shifted from thick rocky walls to thinner walls and plate glass windows. Engineering and building construction technology improved so that taller and larger buildings could be built, and more window space was included.
Large panes of glass attract great deals of heat and the space inside needs to be mechanically cooled. When power is lost in a skyscraper the windows cannot be opened, and the building has to be vacated because its temperature cannot be regulated.
Sung was a biology major before becoming an architect, and her deep knowledge of human skin characteristics inspired her to create skin for buildings. Thermo-bimetal requires no control and no energy to manipulate itself. The material is a lamination of two different metals and two different coefficients of thermal expansion. When heated one of the metals will expand faster than the other and result in a curling displacement.
Development of the thermo-bimetals included many different shapes and configurations, and a finger-like set of strips is the current method being tested. The idea is that the material will act as a sun shading device and a ventilation system. When the sun hits the surface of the structure each individual finger moves toward the heat. Each finger is calibrated to get the desired performance based on location within the piece itself and orientation toward the sun.
Future applications of this living breathing material are incredible. A four story house in China begins as a tall glass box sheathed in a thermo-bimetal screen that can open and close as the sun moves around its surface. Areas can also be closed off for privacy at different times of the day.
Doris is working on double pane glass and inserting the metal between the two panes. When the sun heats the space between panes the metal should morph and create window shade for the building. Another project in the research phase is intended to move back and forth in waves like cilia or eyelashes.
The showpiece of her developmental work takes inspiration from spiracles, a method that grasshoppers use to regulate their body temperature. A honeycomb-like structure can be built that when treated with the bimetal might allow air to flow through a building's walls instead of opening windows.