mylar/polyethylene c))motion plastic, 2.5 mils thick
polyethylene screen
c))motion film heat-staked to screen
materials selected to curl open at 120 F

However, designers rarely employ bimetallic strips more widely- a natural consequence of the material's high cost, small range of motion and limited palate of colors and sizes.

However, a plastic analog of the bimetallic strip is possible- which I've named "c))motion". Plastics have ten times the expansion coefficient of metal, and thus exhibit ten times the range of motion for the same range of temperatures. Plastics can be colored, stamped, rolled out into sheets the size of football fields, never rust and are very inexpensive.

A typical c))motion film consists of a 1 mil layer of mylar bonded to a 1 mil layer of polyethylene. This film will lay flat at room temperature, yet curl into a tight circle at 120 F. If the plastic is tinted black, sunlight efficiently heats the film, so even on a winter day the film uncurls at noon, and re-curls at night.

A brief animation illustrating the fundamental bi-plastic effect may be found here.

Ventilation control- strips placed on a drop-ceiling tile let hot air out, but shut and seal warm air in- thus passively maintaining a comfortable working environment without complex control systems. A similar idea can be used to ventilate attic crawl spaces, or moderate a greenhouse or even cover an entire field of seedlings to stimulate early germination..

Daylighting- strips or flaps of c))motion can be placed within or above the surface of a plate glass window. When exposed to bright sun, they bend down and block the ingress of light. At night or on a cloudy day, they bend out of view.

Embraceable furniture- similar to the above applications, a c))motion metallized film behind a layer of fabric on a chair or couch, will reflect heat to a seated person on a cool winter day, but allow ventilation and greater comfort on a warm, moist day.

Solar energy- someday, when thin-film solar cells are perfected, the same principle might be employed to track the sun --increasing solar energy gain without the use of motors or mechanical linkages.

Sculptural- the panels can be mounted as a decorative light screen for a south facing hallway. On sunny days, the strips bend away from the wall and track the motion of the sun. They move and wave as clouds float by, interacting with visitors as their shadows obscure the sunlight.