Bionic Bugs

In a large, empty room at the University of California, Berkeley, a giant flower beetle sits on the floor. Like most beetles, it has a segmented body, six legs, and a pair of wings. But there’s something a little different about this one: it’s wearing an electronic backpack that’s wired to its wing muscles and brain.

An engineer in the room taps a button on his laptop and instantly the beetle’s wings begin to vibrate, rousing it into flight. Pressing another key stops all wing movement mid-flight. The beetle drops to the floor — a little stunned, perhaps, but unharmed. If it sounds too bizarre to be true, just check out this video on YouTube or view it below.

This bionic bug is the latest creation of a government-funded research project whose goal is to invent a new kind of military surveillance by fusing living insects with innovative electronics. The Defense Advanced Research Projects Agency (DARPA) has already invested $12 million since 2006 in the sci-fi venture, hoping someday to deploy insect-machine hybrids as inconspicuous army scouts. A diverse group of scientists from across the nation is working to help make DARPA’s vision of remote controlled insect spies a reality. Although any military application is still a long way off, biologists and engineers are already finding the research useful.

In a new study, electrical engineer Hirotaka Sato and his Berkeley colleagues embedded tiny electrodes in beetles’ brains and muscles, allowing the researchers to remotely start and stop flight, make the insects turn right or left, and even trigger changes in elevation.

The Berkeley research demonstrates “the first wireless control of any insect in free flight,” said John VandenBrooks, an Arizona State University insect biologist and co-author of the study, which was published this past October in the journal Frontiers in Integrative Neuroscience.

According to the study, remotely controlled flying insects could “serve as couriers to locations not easily accessible to humans,” places where soldiers can’t stroll about unnoticed. As stated on its web site, DARPA hopes to eventually use insect cyborgs to carry “sensors, such as a microphone or a gas sensor, to relay back information gathered from the target destination.”

The Berkeley team worked with green June beetles and giant flower beetles, which can grow to the size of a human palm. “Beetles are really ubiquitous and really strong fliers, and they can carry a large payload,” said VandenBrooks, explaining how these bugs can fly even while toting the hefty electronic backpacks that process and power the electrodes wired to their bodies.

After implanting radio-equipped electrodes into the adult beetles’ brains and wing muscles, the researchers used a laptop to wirelessly activate the implants, which delivered pulses of electricity. Exciting the beetles’ brains allowed the team to start or stop flight on command. Exactly why this worked so well remains unclear, since the electrodes affected a sizeable and unspecified brain region. “We must have been stimulating some part of the motor area,” VandenBrooks suggested. To change the direction of flight, the researchers excited either the left or the right wing muscles.

Before the Berkeley study, most advances in insect cyborg research happened at Cornell University’s Laboratory for Intelligent Machine Systems, where some researchers focus on moths — specifically, hawkmoths, which breed quickly and can carry large payloads during flight. Some Cornell researchers have experimented with implanting electrodes during early stages of metamorphosis, so the adult hawkmoths emerge as cyborgs. These implants allowed for some preliminary control of wing movements and established the surgical techniques later used and modified by others, including the Berkeley team.

Although DARPA hopes insect-machine hybrids will someday facilitate the military, a fleet of stealthy insect spies won’t be breaking out of the lab any time soon. “It’s the whole idea of the fly on the wall technology,” said Tim Reissman, a mechanical engineer at Cornell. “Currently, our fly is this relatively huge insect,” he added, emphasizing the need for both smaller insects and lighter devices before the cyborgs will be of any help to the armed forces. VandenBrooks, co-author of the Berkeley study, agreed: “Some people definitely blow it out of proportion. We’re not even close to having any applications of that kind.”

Perhaps the greatest hurdle to a practical military application of bionic bugs is the issue of power. Any cyborg electronics will require a power source, which usually means heavy batteries that weigh down even large insects like flower beetles and hawkmoths. Imagine a giant bug the size of your hand, lugging a backpack of batteries and microchips, trying to discreetly carry out its reconnaissance. Not exactly inconspicuous. But some researchers are determined to resolve the issues of power and size.

With the guidance of lab director Ephrahim Garcia, a mechanical and aerospace engineer, Reissman and others at Cornell have tried to create electronic devices powered by the moths’ own movements — an attempt to circumvent the dependency on cumbersome batteries. To accomplish this, they use piezoelectric material, which turns motion “into a voltage that can be utilized to power other things,” Garcia explained. Attaching a piezoelectric device to a moth turns the vibrations of its body during flight into a power source. The ultimate goal is functional battery-free sensors, such as a tiny camera or “a simple GPS monitor — the world’s smallest,” Garcia said.

Reissman is optimistic about their success. His colleagues are working to build miniature mechanical systems compatible with the low voltages harvested from a moth’s movements. According to Reissman, their devices are almost efficient enough for takeoff.

Not everyone thinks it’s feasible to extract sufficient energy from insect movement to power any mechanical instruments of practical use. “I’m skeptical,” said Reid Harrison, a University of Utah bioengineer who builds electronic backpacks for locusts in order to study how their nervous systems help them escape predators. “These animals only generate so much mechanical force. Even using piezoelectric material, it’s a very difficult challenge.”

Despite the obstacles to true energy harvesting, researchers persist. At the University of Washington, Brian Otis is designing a battery-free in-flight monitoring device for hawkmoths. “There is data for insects showing huge differences in temperature between rest and movement,” he explained. Otis believes the high internal heat of a flying insect is another potential power source.

Because DARPA provides the funding, scientists who take on the challenge of creating insect cyborgs are ostensibly working toward the ultimate service of the government and army. But so far, the synthesis of insect and machine has benefited science more than the military. Insect cyborgs are not only pushing engineers to build devices — like Cornell’s GPS system — that are smaller, lighter and more efficient than anything they’ve made before, they could give scientists access to entirely novel information.

It’s very difficult to measure a living organism’s internal processes without somehow restraining it and disturbing its natural behaviors. But the more scientists learn about safely fusing living animals and technology, the better they become at monitoring the many important biological processes that happen inside those animals, without keeping them caged up or tethered in labs.

Bionic bugs could soon provide biologists with an unprecedented ability to study insects in their natural environment. Imagine breeding cyborg moths and beetles outfitted with tiny self-sufficient GPS monitors and chemical sensors — then releasing them to the skies and forests.

“We want to monitor body temperature, metabolic rate, flight speed — we want to map where they are going, map their life history. A lot of this is really unknown,” said VandenBrooks, co-author of the Berkeley study. “Animal tracking devices and how long they last are an important issue,” said Cornell’s Reissman. “Making better, longer lasting devices would be very advantageous to understanding biological systems.”

Focusing on the nervous systems of insects has also proven beneficial to scientists. It might seem trivial to study the brains and behaviors of bugs, but nerves — the individual cells of the nervous system — are so complicated that researchers need to tightly concentrate their efforts to make progress. “It’s a very valuable way to approach and study neuroscience,” the University of Utah’s Harrison said. “It turns out biology is really, really complex. A housefly has a quarter million neurons in its brain — and that’s just a housefly!”

“It’s such a sci-fi approach that some people see no feasibility or use for this research,” said Reissman, “but the truth is that each of these research areas needs advancing. We’re going to keep seeing good science come out of this.”