A superhero cyborg cockroach could help in rescue operations- here's how

The answer is in the solar cell

“The body-mounted ultra-thin organic solar cell module achieves a power output of 17.2 megawatts, which is more than 50 times larger than the power output of current state-of-the-art energy harvesting devices on living insects,” said Kenjiro Fukuda, a senior research scientist at RIKEN.

The cyborg cockroaches use a system that includes a tiny wireless organic solar cell module, just 0.004 mm thick. This is mounted on the dorsal side of the insect's abdomen.

The 'cyborg' has been developed by scientists to aid in disaster recovery, investigate hazardous locations, or monitor the environment.

For the deployment of cyborg insects to be effective, their human handlers must be able to maintain control over them for extended periods.

To accomplish this, researchers used a tiny rechargeable battery that enables control of the cockroaches' leg segments wirelessly.

However, the need for the cockroach to return and recharge could interfere with time-sensitive tasks. Although docking facilities for recharging the battery were one possible option, the researchers decided that the best answer was to have an onboard solar cell that could ensure a continuous charge to the battery.

“Keeping the battery adequately charged is fundamental—nobody wants a suddenly out-of-control team of cyborg cockroaches roaming around,” noted the researchers in a press statement released on Monday.

While advanced, this is not the first time researchers have developed a cyborg insect. In 2021, Hirotaka Sato, who also participated in the current project, and his colleagues at Nanyang Technological University in Singapore, implanted electrodes into special sensory organs on the side of Madagascar-hissing cockroaches. The electrodes were connected to tiny computers, and researchers could 'steer' the insect by applying a current to the organ.

Earlier experiments

A group of scientists at Washington University re-engineered the olfactory system of the American grasshopper, "Schistocera americana," to invent biological bomb detectors in 2020.

In 2018, two researchers from the University of Connecticut created an experiment that resulted in cyborg-like cockroaches, which could one day assist in everything from search and rescue operations to national defense.

Moreso, the US Defense Advanced Research Projects Agency invited scientists to submit "innovative proposals to develop technology to create insect-cyborgs" back in 2006.

To better understand the new 'robo-bug' in town, IE bugged Kenjiro Fukuda- one of the artificial insect's creators- for an exclusive interview.

The following conversation has been edited for clarity.

IE: What is the purpose of the Robo-bug?

Cyborg insects have been proposed for applications such as urban search and rescue. Body-mounted energy-harvesting devices are critical for expanding the range of activity and functionality of cyborg insects.

Current cyborg insects don't have energy harvesting devices on their body because the area and load of the harvesting device considerably impair the mobility of tiny robots. This research aims to include energy harvesting devices on cyborg insects so the electronic device system can be recharged.

IE: Why have you chosen to use Madagascar hissing cockroaches?

There are a few reasons for using Madagascar hissing cockroaches in this study. First, they are one of the biggest roaches in the world, and their body length reaches 5-7 cm. The size is important for generating larger power using solar cells because the area determines the power output.

Second, they have a long lifespan of up to five years and are relatively resistant to the environment.

Third, they do not fly. This makes controlling the cockroach's motion using stimulation wires easier. For the above reasons, they are widely used insects for cyborg insect research. However, we can use our technologies with other insects in the future.

IE: Can you elaborate on the material mounted on the cyborg?

We use polymer substrate (transparent polyimide) and fabricate organic solar cells for ultra-thin organic solar cells. Essentially, the mounted material consists of several components: a transparent electrode (indium tin oxide), a charge carrier layer ( oxide metals), a photoactive layer (organic semiconducting materials), and a top electrode (silver).

We use commercially available Si chips and lithium polymer batteries for circuits and a battery.

IE: You talk about inspecting hazardous areas or monitoring the environment? How would that work in practice?

The current system only has a wireless locomotion control system but not enough to inspect hazardous areas or monitor the environment. For these scenarios, we would need to integrate other required devices, such as sensors and cameras, into our cyborg cockroaches.

The main target situation will be inspecting hazardous areas. For example, if a massive earthquake hits an area, people would be buried in the rubble, making it difficult and dangerous for humans to explore. In such an environment, we believe that small insects can quickly enter the rubble and contribute to the rescue of victims.

IE: How long can the cockroach run on the solar cell?

In the current system, a 30-minute charge of our solar cell module under sunlight conditions can allow a two-minute operation of wireless locomotion control.

We continuously communicate wirelessly between the external server and receiver on the insects, which causes enormous power consumption. The running time depends on how frequently we do wireless communication.

Additionally, we are now trying to enhance the power output of our ultra-thin organic solar cells. The balance between charging and consumption power will also be improved.

IE: How did this project come into being?

This multidisciplinary project necessitates a wide range of knowledge, including electrical engineering, mechanical engineering, and biology.

Although each professor is an expert in their respective fields, we struggled with how to combine them. Due to the Covid situation, it was nearly impossible for team members in RIKEN to understand deep techniques for cyborg insects. Similarly, researchers in Singapore (Prof. Sato’s group) could not learn the fabrication process of ultrathin organic solar cells.

For several years, we struggled with how to create a synergistic effect with our strengths to create cyborg insects. Fortunately, an Umezu group student, Yujiro Kakei, was the first to join the team of researchers in 2021.

Kakei has a deep knowledge of insects because he is an insect geek and an "Otaku" [ a person having an intense or obsessive interest, especially in the fields of anime and manga]. He quickly learned about our ultra-thin organic solar cells and combined this with his mechanical engineering expertise. His input established every required technique to achieve integrated devices for cyborg insects.

This project is a collaboration of many scientists. It includes Prof. Hirotaka Sato of Nanyang Technological University (NTU), Singapore and Prof. Umezu of Waseda University, and the RIKEN team, which specializes in the fabrication of ultra-thin organic solar cells.

The research group has recently received national funding from the Japan Science and Technology Agency under the JST-MIRAI program to accelerate the project.