MIT engineers have taken inspiration from nature, creating tiny robot fireflies which light up, weighing less than a paper clip. For now, the miniature drones don’t look like the real thing so much, but one day, these robots could easily pass as real insects.

In 2021, researchers suggested possible uses, such as acting as artificial pollinators. Also, they suggested the robot bugs could “search for survivors amid the rubble of a collapsed building.” 

It may remind you of a sci-fi episode where robot bugs attempt to fill the role for bees or search amid the ruins for signs of life – but this is a dystopian real-world possibility.

Soft Bug Robots

Using a new fabrication technique, they devised “artificial muscles” called soft actuators that flap robot wings for propulsion.

“Unlike drones, which require propeller-like systems to move around, the robot lightning bugs use artificial muscles capable of flapping built-on wings. That means that MIT’s robot is actually flapping wings to take off, instead of forcing air underneath it like a propeller system,” reports MSN. 

This technique meant the drones, weighing less than a gram, used 75 percent lower voltage and could carry 80 percent more “payload.”

A soft actuator comprises 20 microscopic layers of elastomer, rubbery material that can be stretched and return to its original shape. After rolling the material into a “squishy cylinder,” it is placed between tiny carbon nanotube electrodes (1/50,000 the diameter of a human hair) that squeeze the elastomer to make the wings flap.

The more elastomer layers, the less voltage is needed to make the wings flap. So, they worked out how to get as many layers as possible, removing air bubbles with a vacuum process.

Insect-Inspired Drones

With 20-layer actuators, the bug robots can carry three times their weight. However, keeping their scale small meant they couldn’t carry much in the way of electronics or sensors. Consequently, the drones couldn’t communicate with each other and were difficult to track.

Video from MIT:

Enter Robot Fireflies

Then, the engineers found a way to communicate with light, taking inspiration from lightning bugs. To accomplish this, they apply electroluminescent zinc sulfate particles to the topmost squishy layer. Along with this, they needed to find a way to allow light to pass through the electrodes. They solved this problem with carbon nanotubes just a few nanometers thick, transparent enough to let the light shine through.

A different chemical combination of particles can produce blue, orange, or green light. Also, the researchers applied masks over the top to spell out the letters M-I-T.

When the robot moves at a high frequency, the soft actuator creates an electric field that causes the zinc particles to emit light. A researcher from Colorado, Kaushik Jayaram, described it as “wingbeat synchronized flash generation.”

Only 3 percent more energy is needed to get light, and the overall weight is only 2.5 percent heavier. Possibly, applying electroluminescence even improves how the artificial muscles function.

How Will Robot Fireflies Be Used?

By flashing lights, the drones can communicate in a basic way. They could signal SOS, for instance, during search and rescue missions. On the other hand, they could also signal for any number of reasons, depending on who oversees their flight.

Similarly, researchers at the University of Pittsburgh recently created bug-inspired robots to enter dangerous environments. 

“These robots could be used to access confined areas for imaging or environmental evaluation, take water samples, or perform structural evaluations,” said Junfeng Gao, who led the work as a Ph.D. student in industrial engineering at the Swanson School of Engineering. “Anywhere you want to access confined places—where a bug could go but a person could not—these machines could be useful,” SciTech Daily reported.

At the size of crickets, they can jump along on sand and even “hop across water.”

Insect Spies

As the video from Motherboard below suggests, the potential for various bug robots to spy on people (or worse) is also a big concern as people continue to lose privacy globally.

In other experiments, scientists in North Carolina have applied tiny electronics to real insects, in one case developing remote-controlled cockroaches. Again, the researchers point to a potential for search and rescue missions.

Video by Motherboard: 

Motion Tracking with iPhones

As for the robot fireflies, the researchers designed a motion-tracking system using iPhone cameras and software. Impressively, the accuracy was nearly as precise as motion-tracking systems costing thousands of dollars.

For now, they can’t track the flying bugs in real-time. In the future, they plan to improve the tracking system and find a way for the robot bugs to communicate with each other more like real fireflies.

So far, the robot bugs have only been hovering in laboratories but could sooh be flying outdoors. Then, swarms of tiny bug robots might fly along with a larger one that would track their locations, suggested Pakpong Chirarattananon, a researcher from Hong Kong.

By mimicking nature, scientists have made startling advances recently. For example, researchers in Australia made a quantum leap by mimicking organic molecules. They expect to revolutionize quantum computers and learn much more about how nature works at the smallest scales.

Video from MIT:

Featured image: Fireflies by Jerry Lai via Flickr, (CC BY-SA 2.0)