The first thing to understand about the Madagascar hissing cockroach, a dark-brown invertebrate as long as an index finger, is that it lives up to its name. When it feels threatened, it hisses by quickly letting air through holes in its back. The result is a rattle similar to a snake’s tail. Weird but cool.
The second thing about the Madagascar hissing cockroach is that scientists have used it to create insect robots that could one day be used to monitor the environment or help with urban search and rescue missions after natural disasters. Also weird. Also cool.
In a new study published Monday in the journal npj Flexible Electronics, an international team of researchers revealed that they have designed a system that can remotely control the legs of cockroaches from a distance.
The system, which is basically a cockroach backpack connected to the creature’s nervous system, has about 50 times more power output than previous devices, and is made with ultra-thin, flexible solar cells that don’t impede the roach’s movement. Pressing the button sends an electric shock to the backpack, which induces the roaches to move in a certain direction.
If you’re freaked out, let me explain.
Rise of the Cockroach
Cockroach robots are not a new idea.Back in 2012, researchers at North Carolina State University were experimenting withshowing that small animals can be remotely controlled to walk along the track.
The scientists did this by hooking up the backpack and attaching wires to the cockroach’s “tail whiskers,” which are two appendages at the end of the abdomen that are basically sensory nerves. One on the left and one on the right. Previous research has shown that an electrical pulse on either side can stimulate the cockroach to move in that direction, allowing the researchers to control the movement.
But to send and receive signals, you need to power the backpack. You might be able to use a battery, but eventually, the battery will run out and the robot cockroach will be free to disappear into the fallen leaves.
Riken’s team designed the system to be solar-powered and rechargeable. They attached the battery and stimulation module to the roach’s thorax (the upper part of its body). That’s the first step. The second step is to ensure that the solar cell modules can adhere to the cockroach’s abdomen, the segmented lower part of the body.
While humans have found the best way to wear a backpack, it’s not the same for insects. For example, the segmented nature of a cockroach’s abdomen allows it to twist or flip itself if it enters the furry. If you slap a sticky backpack or rechargeable battery on it, you restrict its movement and rob it of its mobility.
To overcome this problem, Riken’s team tested many thin electronic films, put their cockroaches through a series of experiments, and watched how the cockroaches moved according to the thickness of the films. This helped them decide to use modules that are about 17 times thinner than a human hair. It attached to the abdomen without greatly restricting the roach’s degrees of freedom, and also stayed there for about a month, significantly exceeding previous systems.
Then, the fun part (I assume): remote control of insects.
In a series of experiments, the team showed how the system could guide cockroaches on demand via a wireless system. You can see above.
And, for now, that’s all they can do.
“The current system only has a wireless motion control system, so it is not enough to prepare for applications such as city rescue,” said Kenjiro Fukuda, a flexible electronics expert at Riken Japan. “By integrating other required equipment such as sensors and cameras, we can use our robotic insects for such purposes.”
Cameras may require more power, but some sensors use so little power that they can be integrated into today’s systems, Fukuda noted. If cameras are available, they can be very low resolution.
Notably, thanks to the design of the ultra-thin solar cell, Fukuda notes that it could be applied to other insects — possibly even creating an army of robotic insect-flying insects controlled by human hands. Beetles and cicadas are potential candidates.
Insect robots have a little time. In July, Rice University researchers unveiled their spider “necrobots”—the insect-machine hybrids they use to create the world’s creepiest claw machines.
But those spiders are dead. Cockroaches are not.
I must admit, when I saw the image of the cockroach crawling in a certain direction, I felt a strange… guilt. Or something like that, maybe. I wonder if these creepy crawlers understand that their legs are being manipulated against their will and if the process is painful. Fortunately, “according to research related to insects, cockroaches don’t feel pain,” Fukuda said. Yo.
However, in recent years there have been several studies looking at how insects experience emotional states and discussing the ethical implications of such research. A recent article in the journal Undark also discussed the issue of insect pain, noting that understanding of insect consciousness is still lacking.