Sunday, June 10, 2007

Smart socks

Welcome to the age of smart materials.

A alliance of engineers, chemists, physicists, and computer experts are working to endow materials such as concrete and metal with "nervous systems" and "intelligence." And they are creating new structural materials as subtly responsive to their environment as the skin of a dolphin or a butterfly's wing.

For example, today's airplanes have un-smart skins of sheet metal. The smart plane of the future will be clothed in a multilayered composite material with built in "nerves" and "muscles." Embedded fiber-optic threads will monitor the skin for micro-cracks or dangerous stresses. Electronic circuits built into the skin will process information on-the-spot from the fiber-optic network. Millions of tiny pressure-sensitive actuators will respond by stiffening the skin or damping out vibrations.

A smart aircraft skin might also incorporate billions of tiny vacuum pores that open and close in response to the flow of air over the surface, correcting for turbulence that might decrease the fuel efficiency of the plane -- or cause an accident.

Or imagine concrete for a bridge with its own "immune system," chemicals that detect and respond to weathering of the concrete or corrosion of reinforcing rods. Imagine concrete threaded with fibers filled with adhesive; if a crack develops in the concrete, the fibers rupture and release a crack-sealing glue.

The goal of "smart-materials" researchers is to animate the inanimate world. They even have their own publication: "The Journal of Intelligent Material Systems and Structures."

While these clever scientists and engineers are putting their heads together to endow bridges and airplanes with self-awareness and animation, let me suggest a few smart products I'd like to see.

--Snow-No-More Driveway Compound. An asphalt-based material that stores up solar energy chemically during the summer, by a kind of photosynthesis, and releases the energy as heat when triggered by the appropriate combination of cold and moisture. No more shoveling.

--TidyTable Dinnerware. Dishes that can be activated -- say, by a loud clap -- to clean themselves. Food soil would be detached, broken up, and dispersed as harmless gases by tiny, surface-embedded nanorobots. Like antibodies in the human immune system, these nanorobots would recognize any material that is not self, and attack. Dishes would never leave the table and would always be sparkling clean.

--Sun-'n-Shade Roofing System. Surely, no material is more in need of an intelligent replacement than the standard American roofing shingle. What we require is a smart material that changes color with the season, becoming reflective in summer and absorptive in winter, cooling or heating the house appropriately. A network of capillaries embedded in the material would support a solar hot water system, and might even allow the house to cool itself by sweating during hot weather. And, of course, the material would be photoelectric, generating electricity for the home.

--Springback Cotton. This fabric would incorporate threads of nitinol, a nickel-titanium alloy that remembers its shape. Below a certain temperature, nitinol will take any shape it is bent into, but when heated returns to its original shape. Heated in a clothes drier, Springback cotton will "spring back" into its original, unwrinkled state. No ironing will be necessary. At last, we'll have the comfort and feel of cotton with the convenience of polyester.

--ElectroFloor. A flooring material incorporating a piezoelectric polymer such as polyvinylidene fluoride. These materials convert mechanical pressure into electricity. My wife complains that I am always nervously pacing around the house. By connecting the ElectroFloor carpet to storage batteries, my pacing will generate useful energy. Even the cat's nocturnal ambulations will help cut the electric bill.

--LustraBowl Toilets. No household chore is more unpleasant than cleaning the toilet. A toilet bowl whose interior surface was coated with piezoelectric ceramic could be electrically stimulated to vibrate vigorously each time the toilet is flushed, dislodging soil, and, by imparting high-frequency sound to the flush water, cleaning the bowl ultrasonically.

--Perfect Rest Mattress. This foam mattress would be made of a polymeric gel that dilates or contracts when charged electrically or neutralized. Optical fibers in the surface of the mattress would sense every twist and turn of the sleeper's body and send this information to a microcomputer embedded in the mattress. The computer would control a network of electrodes stimulating the polymer gel, regulating the firmness of the mattress with infinite subtlety. Comfort would be maximized for each part of the body, and, in the case of a double bed, firmness could be customized for each sleeper independently.

--w/ALL-Paper. The genius of the iPhone is that its active surface can be anything you want it to be. A menu. A keyboard. A video display. A photo album. And now Sony has announced a cardboard thin, flexible video display. I envision the day when the walls of the house are "papered" with touch-sensitive liquid-crystal display. Any wall can be a TV screen of any size, including the shower stall or the ceiling over the bed. Art can be "hung" electronically. Redecorating will be as simple as tapping a few keys on your computer.

--Chameleon Brand Footwear. Socks made of this material would sort themselves in the drawer by changing color to match their mate. In an age of smart materials, no one should have to go to work with mismatched socks.

Discuss this essay and more over on the Science Musings Blog.