PATTERNED NANOTUBE ARRAYS. Nanometer-wide tubes of carbon atoms, made amid fiery arc discharges, have been used in a number of ways, such as for tips in scanned probe microscopes. Researchers at ATMI, a company in Danbury, CT, produce films of nanotubes in a chemical process that uses catalysts carefully deposited on large-area substrates. Mats of nanotubes grow only atop the catalyst in pre-determined places to form desired nanotube patterns. The tubes are good emitters of electrons and thus the process lends itself to the job of enabling flat-panel displays, and is, fortunately, compatible with silicon processing. (Xu and Brandes, Applied Physics Letters, 26 April.).