Last year Asier Marzo, then a doctoral student at the Public University of Navarre, helped develop the first single-sided acoustic tractor beam—that is, the first realization of trapping and pulling an object using sound waves from only one direction. Now a research assistant at the University of Bristol, Marzo has lead a team that adapted the technology to be, for all intents and purposes, 3-D printable by anyone (with some assembly required, of course).