It might sound like science fiction, but all the pieces are falling into place for a future where remote-controlled cyborg cockroaches could help map out disaster areas and search for survivors. Researchers at North Carolina State University (NCSU) have been working on the "biobots" project for several years, and now two new studies have looked into how accurately the bugs' movements can be tracked, and how much autonomy they need to be efficient explorers.
While other research teams are making insect cyborgs using locusts and dragonflies, the NCSU team makes use of Madagascan hissing cockroaches, which are fitted with electronic backpacks containing a simple computer chip, a wireless receiver and transmitter, and a microcontroller. That microcontroller is wired into the insect's sensory organs to make it move on command: electrical signals sent into its antennae tell it to turn left or right, while stimulating the cerci – organs in the rear of the abdomen – acts like a gas pedal.
We've followed the NCSU biobot project pretty closely over the years, from the first announcement in 2012, to the development of the software and hardware that drives the roaches, to using drones to shepherd them around. Now, the team is studying how they might explore a new space on their own, and how much guidance should be given to nudge them in the right direction.
For the first study, the researchers wanted to check the accuracy of the distance and direction measurements recorded by their back-mounted equipment. This was done by simply watching the biobots with their own eyes, and comparing that to the automatic data that the system collected about where and how the bugs were moving. The team concluded that the equipment was taking accurate readings of the insects' movements.
The second study was a little more in-depth. The researchers wanted to investigate how far and how fast the biobots would move to allow them to figure out how many of the insects might need to be deployed in order to quickly map out an unusual environment, such as a collapsed building.
"This is practical information we can use to get biobots to explore a space more quickly," says Edgar Lobaton, a co-author on both papers. "That's especially important when you consider that time is of the essence when you are trying to save lives after a disaster."
To answer these questions, the researchers let the roaches loose in a circular, enclosed arena. Some were allowed to wander freely with no external stimulation to direct them, while others were sent commands at random to move either forward, left or right. Since the bugs are the first responders and the human operators don't have line of sight, direct remote steering isn't an option.
The two groups showed very different behavior as a result: those exploring on their own tended to stay close to the walls, leaving large patches of unexplored space in the center of the circle. But the bugs that received random pulses were five times more likely to wander away from the walls and fully explore the area.
"Our earlier studies had shown that we can use neural stimulation to control the direction of a roach and make it go from one point to another," says Alper Bozkurt, a co-author of both papers. "This [second] study shows that by randomly stimulating the roaches we can benefit from their natural walking and instincts to search an unknown area. Their electronic backpacks can initiate these pulses without us seeing where the roaches are and let them autonomously scan a region."
The researchers will present the two studies at the IEEE International Conference on Acoustics, Speech and Signal Processing next week.
Video of the biobots exploring a circular, enclosed arena can be viewed below.
Source: North Carolina State University