Insects are the most successful creatures on the planet, endowed with millions of years of evolution. Attempting robots that mimic the insect form has turned out to be a complex affair. Therefore researchers planned to turn bugs into robots to exploit insects’ natural abilities to achieve feats that are not currently available with purely mechanical technology such as drones
Research into Hybrid Insect Micro-Electro-Mechanical Systems (“HI-MEMS” or “cyborg insect drones”) started in 2006 when the Defense Advanced Research Projects Agency (“DARPA”) requested proposals from researchers to create cyborg insect drones. “Hybrid insect” drones would be created using live insects, electronic circuitry, and other technologies. These HI-MEMS could then be equipped with sensors to conduct military and civilian missions
For various reasons, hijacking insects’ bodies may be a reasonable solution to the problems inherent in creating miniature drones for various applications. First, insects are naturally self-powered. This means that HI-MEMS can operate for longer periods of time than their mechanical counterparts and do not always need to be controlled. Cyborg insects have a number of disadvantages compared to actual robots, such as limited life spans. The advantage is that they have ready-made platforms, avoiding the necessity of making a lot of small parts. They also use less power than comparable robots. One big advantage is that the insect cyborg can overcome obstructions by itself.
Also, insects have naturally evolved to survive harsh conditions and environments. Furthermore, insects possess natural abilities that may be difficult to replicate in mechanical drones. For example, locusts possess a strong sense of smell and can be trained to detect certain odors.
Though flying insects have generally been targeted as host insects to date, future research
may seek to exploit insects’ other innate abilities such as swimming. Finally, insect drones are
relatively less expensive compared to purely mechanical technologies that serve the same
function, which means that the mass-production of HI-MEMS may be commercially feasible.
In the past researchers have experimented with honeybees, beetles, cockroaches, moths, locusts and dragonflies. Based on the insect selected, researchers then connect electrodes to the insect’s muscles, nerves, antennae or brain to manipulate movement. For example, researchers working with cockroaches clip the insect’s antennae and attach electrodes to direct their movement. In experiments using other insects, researchers pierce the creature’s exoskeleton and implant electrodes in the desired location.
Some researchers have created genetically modified insects that can be controlled by light rather than electrical stimulation. Researchers have also found ways to power the electronic backpacks using an insect’s own natural vibrations and solar energy. Eventually, researchers hope to equip HI-MEMS with sensors to transmit audio and video data, detect gases, transmit heat signatures, and even map environments.
These insect drones may have many military applications, one of which is to spy on enemies. Small live camera-carrying could fly undetected into locations where humans could not go. These little inconspicuous insects are able to track enemies behind them and provide intelligence data. Other applications of these insects may be for the spread of biological and chemical agents in the territory of the enemy. Or, for example, to attack certain enemy equipment, for example, breakdowns of their radio stations, damage to their wires and networks.
Draper’s work on the DragonflEye program
The smallest aerial drones mimic insects in many ways, but none can match the efficiency and maneuverability of the dragonfly. Now, engineers at Draper are creating a new kind of hybrid drone by combining miniaturized navigation, synthetic biology and neurotechnology to guide dragonfly insects. The system looks like a backpack for a dragonfly. Dragonflies are interesting because they are found worldwide and are very robust and agile fliers for their small size.
Common dragonflies weigh around 600 milligrams, can reach accelerations up to 9 gs, and are known to migrate over great distances. Mechanical fliers of comparable size are far less efficient at producing lift, stabilizing flight, and storing energy. This inefficiency creates a fundamental challenge: Mechanical fliers can carry only very small power sources, which means that they have enough power to fly for only very brief periods of time. The DragonflEye system doesn’t require a power source for flight, only for navigation. It can operate indefinitely due to the insect’s ability to replenish energy from food and the navigation system’s ability to harvest energy from the environment.
DragonflEye, an internal research and development project at Draper, is already showing promise as a way to guide the flightpath of dragonflies. Once they get it to work, this approach, known as optogenetic stimulation, could enable dragonflies to carry payloads with Potential applications including guided pollination, payload delivery, reconnaissance and even precision medicine and diagnostics.
Engineers in HHMI are applying techniques in synthetic biology had to develop a way of genetically modifying the nervous system of the dragonfly so it can respond to pulses of light. To do this, the team gave the insect a gene which added light-sensitive proteins called ospins to the neurons. This then allowed the neurons to be activated by the light – sent by an interface in the ‘backpack’ called an optrode. The neurons then kicked into its usual routine of sending signals to the wings to encourage the insect to fly.
DragonflEye has been a team effort between Draper and Howard Hughes Medical Institute (HHMI) at Janelia Research Campus to create new optogenetic tools that send guidance commands from the backpack to special “steering” neurons inside the dragonfly nerve cord. These steering neurons act as a bridge between the dragonfly’s sensors and its muscles, meaning that accessing them provides a much more reliable form of control over how the insect moves. Research at HHMI—led by Anthony Leonardo, Janelia Research Campus group leader—has led to a deeper understanding of “steering” neurons in the nervous system of the dragonfly that control flight.
“DragonflEye is a totally new kind of micro-aerial vehicle that’s smaller, lighter and stealthier than anything else that’s manmade,” said Jesse J. Wheeler, biomedical engineer at Draper and principal investigator on the program. “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 group was able to pack all of the electronics into a tiny “backpack,” meaning that small insects (like bees and dragonflies as opposed to large beetles) can fly while wearing it. Some of the size reduction comes from the use of solar panels to harvest energy, minimizing the need for batteries. There’s also integrated guidance and navigation systems, so a fully autonomous navigation is possible outside of a controlled environment.
Draper is developing tiny optical structures, called optrodes, that can activate the special “steering” neurons with pulses of light piped into the nerve cord from the dragonfly’s backpack. Traditional optical fibers are too stiff to be wrapped around the tiny dragonfly nerve cord, so Draper developed innovative flexible optrodes that can bend light around sub-millimeter turns. These optrodes will enable precise and targeted neural activation without disrupting the thousands of nearby neurons.
“Someday these same tools could advance medical treatments in humans, resulting in more effective therapies with fewer side effects,” said Wheeler. “Our flexible optrode technology provides a new solution to enable miniaturized diagnostics, safely access smaller neural targets and deliver higher precision therapies.”
Draper’s work on the DragonflEye program builds on its legacy in autonomous systems, microsystems, biomedical solutions and materials engineering and microfabrication. This deep expertise extended previous Janelia Research Campus work in energy harvesting and miniaturization to create the insect-scale autonomous navigation and neuromodulation system.
DragonflEye provides opportunities to put technology on some of nature’s most agile insects. For instance, honeybees, whose population has collapsed by half in the last 25 years, could be equipped with Draper’s technology to assist with pollination. One of nature’s greatest pollinators, honeybees contribute more than $15 billion to the value of U.S. agriculture every year. Draper’s tiny guidance system could help stem the loss of pollinators by monitoring their flight patterns, migration and overall health.
Farmers can already use drones to soar over huge fields and monitor temperature, humidity or crop health. But these machines need so much power to fly that they can’t get very far without needing a charge. Now, engineers have created a sensing system that is small enough to ride aboard a bumblebee.
First sensor package that can ride aboard bees
Now, engineers at the University of Washington have created a sensing system that is small enough to ride aboard a bumblebee. Because insects can fly on their own, the package requires only a tiny rechargeable battery that could last for seven hours of flight and then charge while the bees are in their hive at night. The research team will present its findings online Dec. 11 and in person at the ACM MobiCom 2019 conference.
“Drones can fly for maybe 10 or 20 minutes before they need to charge again, whereas our bees can collect data for hours,” said senior author Shyam Gollakota, an associate professor in the UW’s Paul G. Allen School of Computer Science & Engineering. “We showed for the first time that it’s possible to actually do all this computation and sensing using insects in lieu of drones.”
While using insects instead of drones solves the power problem, this technique has its own set of complications: First, insects can’t carry much weight. And second, GPS receivers, which work well for helping drones report their positions, consume too much power for this application. To develop a sensor package that could fit on an insect and sense its location, the team had to address both issues.
“We decided to use bumblebees because they’re large enough to carry a tiny battery that can power our system, and they return to a hive every night where we could wirelessly recharge the batteries,” said co-author Vikram Iyer, a doctoral student in the UW Department of Electrical & Computer Engineering. “For this research we followed the best methods for care and handling of these creatures.”
Previously other research groups have fitted bumblebees with simple “backpacks” by supergluing small trackers, like radio-frequency identification, or RFID, tags, to them to follow their movement. For these types of experiments, researchers put a bee in the freezer for a few minutes to slow it down before they glue on the backpack. When they’re finished with the experiment, the team removes the backpack through a similar process.
These prior studies, however, only involved backpacks that simply tracked bees’ locations over short distances — around 10 inches — and did not carry anything to survey the environment around the insects. Here, Gollakota, Iyer and their group designed a sensor backpack that rides on the bees’ backs and weighs 102 milligrams, or about the weight of seven grains of uncooked rice.
“The rechargeable battery powering the backpack weighs about 70 milligrams, so we had a little over 30 milligrams left for everything else, like the sensors and the localization system to track the insect’s position,” said co-author Rajalakshmi Nandakumar, a doctoral student in the Allen School.
Because bees don’t advertise where they are flying and because GPS receivers are too power-hungry to ride on a tiny insect, the team came up with a method that uses no power to localize the bees. The researchers set up multiple antennas that broadcasted signals from a base station across a specific area. A receiver in a bee’s backpack uses the strength of the signal and the angle difference between the bee and the base station to triangulate the insect’s position.
“To test the localization system, we did an experiment on a soccer field,” said co-author Anran Wang, a doctoral student in the Allen School. “We set up our base station with four antennas on one side of the field, and then we had a bee with a backpack flying around in a jar that we moved away from the antennas. We were able to detect the bee’s position as long as it was within 80 meters, about three-quarters the length of a football field, of the antennas.” Next the team added a series of small sensors — monitoring temperature, humidity and light intensity — to the backpack. That way, the bees could collect data and log that information along with their location, and eventually compile information about a whole farm.
“It would be interesting to see if the bees prefer one region of the farm and visit other areas less often,” said co-author Sawyer Fuller, an assistant professor in the UW Department of Mechanical Engineering. “Alternatively, if you want to know what’s happening in a particular area, you could also program the backpack to say: ‘Hey bees, if you visit this location, take a temperature reading.'” Then after the bees have finished their day of foraging, they return to their hive where the backpack can upload any data it collected via a method called backscatter, through which a device can share information by reflecting radio waves transmitted from a nearby antenna.
Right now the backpacks can only store about 30 kilobytes of data, so they are limited to carrying sensors that create small amounts of data. Also, the backpacks can upload data only when the bees return to the hive. The team would eventually like to develop backpacks with cameras that can livestream information about plant health back to farmers.
“Having insects carry these sensor systems could be beneficial for farms because bees can sense things that electronic objects, like drones, cannot,” Gollakota said. “With a drone, you’re just flying around randomly, while a bee is going to be drawn to specific things, like the plants it prefers to pollinate. And on top of learning about the environment, you can also learn a lot about how the bees behave.”