With what is delightfully being called “The Atomic Pen,” a team of researchers has created what are likely the world’s smallest letters. At left is an array of silicon atoms measuring two nanometers in height, or a little less than one hundred thousandth of a point.
Their technique, documented in today’s issue of Science magazine, makes use of an earlier discovery: that within a certain proximity, individual atoms from the silicon tip of an atomic force microscope will exchange with tin atoms on the surface of a semiconductor. “It’s not possible to write any smaller than this,” said researcher Masayuki Abe, which sounds like a challenge to me: I can already think of one way to make letters that are 8% smaller, using the team’s own technique. Can you? Answers next week. —JH