Tiny backpack puts dragonflies under remote control

With the ability to hover and zip along at high speeds, the dragonfly has inspired robots and micro UAVs in the past – but why reinvent the wheel when nature has already done the hard work? Now, researchers from the Charles Stark Draper Laboratory and the Howard Hughes Medical Institute (HHMI) have developed a system that a living dragonfly can wear like a backpack, allowing engineers to steer it remotely to deliver payloads, conduct reconnaissance and even guide pollination.

This isn't the first time scientists have driven living insects like remote-controlled cars. Cyborg cockroaches may one day come to the rescue in disaster situations, and locusts might make for tiny, cyborg sniffer dogs. In these cases, the systems make clever use of the insects' external organs and behavior – the cockroaches are controlled by stimulating their antennae, which replicates the sensation of brushing up against an obstacle so the bug changes course. In a similar way, scientists make use of the locusts' aversion to heat, generating mild warmth through patches on their sides to steer them in the other direction.

The DragonflEye project is a bit more "in depth" with the Draper team developing "optrodes," structures that work like tiny, flexible fiber optic cables. Capable of directing light around corners at a sub-millimeter scale, these optrodes can be wired into the dragonfly's nerve cord and connected directly to the neurons responsible for steering the insect.

Meanwhile, the HHMI team has genetically modified the dragonflies so that these steering neurons will respond to light, allowing commands to be issued with pulses of light from the optrodes. According to the researchers, the optrodes are precise enough to only fire the desired neurons without affecting those around them, and the whole system fits on the dragonfly's back.

"DragonflEye is a totally new kind of micro-aerial vehicle that's smaller, lighter and stealthier than anything else that's manmade," says Jesse J. Wheeler, the project's principal investigator. "This system pushes the boundaries of energy harvesting, motion sensing, algorithms, miniaturization and optogenetics, all in a system small enough for an insect to wear."

The cyborg dragonflies could find use in the military realm, for reconnaissance or stealthily delivering payloads, but the system might have more public-focused applications too. With the looming threat to our food supply due to declining bee populations, scientists could fit honeybees with the system to monitor their health and migration patterns or directly guide pollination. The optrodes alone might might find applications in the human brain, opening the door for more targeted therapies.

"Someday these same tools could advance medical treatments in humans, resulting in more effective therapies with fewer side effects," says Wheeler. "Our flexible optrode technology provides a new solution to enable miniaturized diagnostics, safely access smaller neural targets and deliver higher precision therapies."

Source: Charles Stark Draper Laboratory