SciTech

Backpack-toting cockroaches can explore disaster areas

A swarm of insects could one day be the most reassuring sight imaginable to someone trapped in a collapsed building.

That’s because researchers at N.C. State are developing technology that equips cockroaches to enter disaster areas and send back information for search-and-rescue missions.

“You may be someone who hates the cockroach, but it could be the cockroach that saves you one day,” said Alper Bozkurt, an assistant professor of electrical and computer engineering at N.C. State who has written two papers on the work.

These enhanced insects – dubbed biobots or cyborgs – have been developed by Bozkurt and others over the past eight years. Working initially with moths and, later, cockroaches, the scientists equipped the insects to pick up sounds too distant or faint to be heard outside the rubble.

“They carry little backpacks with a small microphone and radio,” Bozkurt said. “With the two-way radio, they can transmit sound to the outside and also receive commands.”

Another facet of the technology allows the insects also to send signals to one another.

“It’s a neighbor-to-neighbor interaction that allows someone to build a map,” explained Edgar Lobaton, a robotics engineer and assistant professor in NCSU’s Department of Electrical and Computer Engineering.

“These little agents move around and continuously communicate with each other by sending out radio signals. We are learning to take this information, put it in a computer, and create a map of the area.”

Because GPS systems usually don’t penetrate concrete and steel, signals emitted by the cockroaches could be extremely important in clearing disaster sites, Bozkurt said.

Steering the insects

To conduct the studies, the scientists attach to cockroaches’ bodies a small platform, which carries the electronic transmission devices. The researchers then control roaches by sending electronic pulses to their antennae. Their tendency to swarm – with many cockroaches following the behavior of a few – helps scientists keep the deployed insects within certain parameters.

“They use their antennae in a tactile manner, like a blind person (might use a cane),” Bozkurt said. “If there’s a wall, the cockroach will follow along by dragging their antennae along the wall. The idea is if these biobots can detect tunnels or small passages and send back that information, you can find multiple ways between the victim and the first responders.”

Because cockroaches lack pain receptors, the electronic impulses don’t harm them, and the backpacks are removed once the experiment ends, Bozkurt added.

Another development has been creation of an “invisible fence” to help corral the insects. Between 20 and 100 cockroaches at a time have been deployed in these experiments.

Bozkurt said he began the work almost eight years ago, with moths.

“As a professor, I led a team of graduate students interfacing electronic devices with the insects to steer them from point A to point B.”

However, controlling the flying insects posed a difficulty, Bozkurt said. “You have to tether them. And any disturbance is likely to bring them down.”

The cockroach – in particular the large, wingless Madagascar species – was more adaptable to the lab experiments.

“Cockroaches come in different sizes; some are small and some are large enough to carry larger payloads,” he said. “And they come with different speeds. Some are fast, but others are slow enough that we are able to control them. And they are available.”

In addition, Bozkurt said, the work is a good way to demonstrate the value of insects: “Insects play an important role in our ecosystem.”

The work is carried out by three teams at NCSU led by Bozkurt, Lobaton and Mihail Sichitiu, an associate professor of engineering. It is funded by a $1 million grant from the National Science Foundation CyberPhysical Systems Program.

Roachlike robots

While Bozkurt is running lab experiments with real cockroaches and Lobaton is developing cyborg mapping capabilities, Sichitiu is experimenting with “robots that act like cockroaches,” Bozkurt said.

Sichitiu’s robots with wheels of 6 to 8 inches may be deployed on flat surfaces. Eventually, scientists hope to program robots to mimic insects, climbing walls and investigating small spaces.

Bozkurt admits he has special admiration for cockroaches and spiders.

“The majority of people hate them, but as engineers, we are amazed by their structure, and when we try to build insectlike robots, it’s very difficult. Although millions have been spent, we still don’t have a robot that can act like an insect. It’s much more complicated than your smartphone. They deserve some respect.”

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