As architects try to reduce the amount of energy spent on air conditioning, high-tech electrochromatic glass products that sandwich LCD layers and are dimmable are becoming increasingly common. Nonetheless, they still suck up power, and so that's why Brent Vander Werf's Compliant Shading Enclosure is so interesting. A series of fabric apertures sandwiched in-between layers of doubled-glazing, his system relies on bistable springs that flex according to the heat from the sun itself, opening and closing the gaps as they move.
"The capacitor utilizes prestressed structural strips which deform an aperture by means of a passive thermostat coil actuator. The increasing storage of elastic strain energy is programmed to rotate and close the aperture at a maximum stressed position, at which point, it is capable of releasing the stored kinetic energy with a decrease in heat input, triggering the mechanism to open the aperture instantly."
The bistable springs are basically bi-metallic strips: two layers of different alloys that expand by differing amounts depending on heat. When that happens, the springs bend as the high-expansion alloy pushes against its low-expansion counterpart, adjusting the size of the gap without any human intervention.
Designed to be zero-maintenance and entirely automatic, the system is being trialled in the University of Arizona’s entry for the Department of Energy’s Solar Decathlon Competition. It's also going through the patent process, and hopefully will start showing up in new, winking buildings sometime soon.