"Smart concrete" looks just like its poorly educated cousin, but contains tiny carbon fibers that could make it the future material of choice for buildings or levees. The fibers are thinner than a human hair and measure about 5mm long. But throw a bunch of themabout 0.2 percent of volumeinto the mix and the concrete that results is stronger and more sensitive. According to Professor Deborah D.L. Chung of the State University of New York at Buffalo, who patented smart concrete in 1998, the material's electrical resistancewhich changes with damage or deformationcan be measured with special meters to discover structural weaknesses before they cause damage. Don't get too excited about the prospect of having the smartest foundation on the block, however, since smart concrete has not yet been approved for wide commercial use.