Robotic Fish Lead Schools of Fish From Danger
Humans are creating a dangerous world. Between the development of man-made disasters such as massive oil spills and the use of hazardous equipment like underwater turbines, animals — especially fish — are constantly encountering novel, perilous situations.
Many times they do not live to tell the tale. A new invention aims to curb this sad trend.
Researchers created a robotic fish that can lead schools of real fish out of danger. This technology could potentially be used for other species that move in herds or schools, whether underwater or on land. But first, scientists need to determine what makes one individual amongst a group the "leader."
Maurizio Porfiri, a researcher at Polytechnic Institute of New York University, played the role of Dr. Frankenstein in this study. To create a realistic and convincing robot fish, Porfiri studied leader fish dynamics in schools of bait fish.
He and colleagues found that leader fish distinguish themselves by beating their tales faster and swimming around excitedly to gain attention. Fish in the group are always on the lookout for visual cues and sensory information that guides their decision to on whether or not to school up.
Once a leader has everyone's attention, it rounds up the school and heads out.
Porfiri also discovered that fish of different species and sizes often school together. With that in mind, his team designed a hand-sized black robotic fish, slightly larger than the bait fish.
The goal: use the aquatic automaton to infiltrate the school and take it over.
But first researchers had to recreate realistic swimming mechanisms. Porfiri designed the robot to swim silently, using ionic polymers that respond to electrical stimulation from a battery to drive the fins. This enables the robot to move in a smooth-yet-jerky, darting fashion like regular fish.
Porfiri's vision is that future robotic fish won't need batteries at all. Instead, they will harness energy from small eddies and vibrations in the water.
The team designed their artificial fish to pilot real fish away from underwater turbines. For the most part, such turbines remain experimental. But the potential applications of robotic fish could be much larger.
The current Deepwater Horizon oil spill in the Gulf of Mexico is claiming the lives of numerous species, from fish to turtles to birds. This new technology could be employed to steer animals away from oiled areas.
It could also pave the way for new farming practices. Robot fish could act as aquatic shepherd dogs that guide schools of free range, framed fish across the open ocean. Rather than squeezing thousands of fish into small contained area, fisherman could control and track the whereabouts of their fish using these bots.