Wired - Building a 3-D printer for supercool ice objects

Water may freeze at 32 degrees Fahrenheit, but it prints at about minus 8. This is just one of the insights that Pieter Sijpkes, a professor emeritus at McGill University, has discovered since cobbling together a machine that prints objects by building up ultrathin layers of ice. He and his team have printed a statue, an egg carton, a martini glass, and molds that melt conveniently away. Why ice? Well, it’s cheap and readily available, and low-cost ice models could help inventors design products more quickly. The challenge of printing with ice, besides the very cold temps necessary for the process, was building a machine that’s up to the task…