The attendees for your 1 p.m. meeting have begun to arrive. But they're not coming through the door. Instead, solid, 3-D models magically self-assemble around the table, looking, moving and talking like impressionistic interpretations of their long-distant human counterparts. Professors Seth Goldstein and Todd Mowry, along with Intel Principal Investigator Jason Campbell, are building "claytronic atoms" or "catoms"—centimeter-diameter pellets embedded with electromagnets that will enable them to connect to and move around other catoms. By controlling potentially billions of catoms as a unit, the researchers foresee creating accurate, active models of 3-D objects. For remote conferencing, attendees could be recorded...