Okay, so they still look like Depression-era bath toys, but Maurizio Porfiri's robot fish have come a long way from the coconut-and-tin-foil look they were sporting last summer. In an attempt to further "close the loop" between robotics and nature, Porfiri has continued to tinker with the little leaders by incorporating diving and surfacing into their aquatic repertoire, and it seems to be working: real fish have shown interaction patterns including tracking, gathering, and following in the presence
