Microchips are hot. Literally. As engineers cram more functions and power into chips, they require more energy and, thus, produce more heat than ever before.

To beat that heat, which limits the performance of the computers and other gadgets we use, Silicon Valley is looking to some surprising materials. Chip companies large and small are experimenting with slices of synthetic diamond, pieces of ultrapure glass or even an obscure material only recently synthesized in quantities sufficient to test its properties.