Researchers at RIKEN in Japan have developed remote-controlled cyborg cockroaches that are outfitted with a tiny wireless control module powered by a rechargeable battery coupled to a solar cell. 

Researchers developed a system for creating remote-controlled cyborg cockroaches, complete with a tiny wireless control module powered by a rechargeable battery connected to a solar cell. Despite the mechanical gadgets, the insects may move freely thanks to ultrathin electronics and flexible materials. These accomplishments will contribute to the practical use of cyborg insects. The findings were published today (September 5, 2022) in the scientific journal npj Flexible Electronics by an international team lead by experts at the RIKEN Cluster for Pioneering Research (CPR).

Scientists have been attempting to create cyborg insects—half insect, part machine—to aid in the inspection of dangerous regions and the monitoring of the environment. However, for the employment of cyborg insects to be realistic, handlers must be able to control them remotely for extended periods of time. This includes using a small rechargeable battery to manipulate their leg segments wirelessly.

It’s vital to keep the battery charged—no one wants an out-of-control swarm of cyborg cockroaches crawling around. While docking facilities for battery charging might be developed, the requirement to return and refuel could impede time-sensitive operations. As a result, an ideal option would be to integrate an onboard solar cell that can continually ensure that the battery is charged.

All of this is, of course, easier said than done. To effectively incorporate these gadgets into a cockroach with a small surface area, the technical team had to create a customized backpack as well as ultrathin organic solar cell modules. They also need an adhesive method that would keep the machines attached for extended periods of time while allowing for natural movement.

The study team, led by Kenjiro Fukuda of RIKEN CPR, worked with Madagascar cockroaches, which are around 6 cm (2.4 inches) long. Using a specially made backpack, they connected the wireless leg-control module and lithium polymer battery to the top of the insect’s thorax. This was 3D printed using an elastic material after being fashioned after the body of a model cockroach. The end product was a backpack that flawlessly contoured to the cockroach’s curved surface, allowing the hard electronic equipment to be put on the thorax for more than a month.

The 0.004 mm thick organic solar cell module was installed on the abdomen’s posterior side. According to Fukuda, “the body-mounted ultrathin organic solar cell module achieves a power output of 17.2 mW, which is more than 50 times more than the power output of current state-of-the-art energy harvesting systems on living insects.”

To ensure freedom of movement, the ultrathin and flexible organic solar cell, as well as how it was linked to the insect, proved vital. The scientists discovered that the abdomen changes form and parts of the exoskeleton overlap after closely observing natural cockroach motions. They interleaved sticky and non-adhesive regions onto the films to allow them to flex while remaining connected. When thicker solar cell films or evenly connected films were tested, the cockroaches took twice as long to go the same distance. They also had trouble getting back up when they were on their backs.

The new cyborgs were evaluated after these components were inserted into the cockroaches, coupled with cables that activate the leg segments. For 30 minutes, the battery was charged with simulated sunshine, and animals were trained to turn left and right using the wireless remote control.

“Considering the thorax and abdomen deformation during fundamental movement, a hybrid electronic system comprising stiff and flexible parts in the thorax and ultrasoft electronics in the abdomen looks to be an efficient design for cyborg cockroaches,” Fukuda explains. “Moreover, because abdominal deformation is not limited to cockroaches, our technique might be applied to other insects such as beetles, or even flying insects such as cicadas in the future.”