In an Israeli lab, the world's smallest drone
A team at the Haifa Technion tries to control flight of insects in U.S. Army-funded research.
In a Technion aeronautics laboratory, a pair of scientists are conducting experiments funded by the U.S. Army that would allow them to control the flight of insects from afar, as if they were mechanical flight vehicles.
Instead of building a tiny plane whose dimensions would be measured in centimeters, the researchers are taking advantage of 300 million years of evolution. "In order to build drones the size of an insect, you need systems to monitor and control, and to produce energy," says Technion Prof. Daniel Weihs, who served until recently as the chief scientist of the Ministry of Science and Technology.
The experiments, conducted by Weihs and Dr. Gal Ribak of the Technion, together with researchers from Tel Aviv University, are funded by the U.S. Army. Weihs - a pioneer in aeronautics research using insects and animals - is not prepared to divulge details about the experiments' applications, adding that he himself isn't entirely sure about them.
Their aeronautics laboratory is unusual in that it doesn't contain a single piece of airplane equipment. Instead, it's full of aquariums and boxes brimming with flies, grasshoppers and beetles, and a bowl containing plants for cultivating dragonflies. The temperature is a warm 30 degrees Celsius. A flight simulator - a long, noisy tube-shaped fan - sits in the center of the lab. A grasshopper hangs in mid-air. When the researchers turn on the fan, the grasshopper flaps its wings furiously as it would if it were caught in a gust of wind in the Carmel forest.
In the research's early stages, the scientists examine how an insect's muscles operate at each moment of flight. Two special cameras, positioned over the flight simulator, record every miniscule movement made by a flying insect. In parallel, electrodes inserted in the various muscles document the electronic signals received in the insect's body during flight. Such measurements allow the researchers to identify which electric signals are connected to which movements. Basically, they translate the insect's flight movements into a code comprised of electronic signals. Using this code, the researchers are able to send electronic signals into an insect's muscles, triggering movements.
"We put together a map that says, for instance, that the signal A implanted in muscle B causes the insect to turn to the right," says Weihs. "So I can prepare a program with my own orders for such an insect. I enter the signal C for the D muscle, and it turns to the left."
Research in this field has developed considerably over the past decade thanks to advances in electronic equipment. The Technion lab is one of some five laboratories around the world conducting similar research. The University of Michigan team has been particularly successful, having managed to control the flight of insects from afar, for allotted periods of time. In the Haifa laboratory, researchers have gained control of the flight of insects that are connected to a simulator. They can give a series of commands that control the flight movements of insects for a few minutes.
"The important thing is not just to control the insect from afar," explains Ribak, an expert in animal biomechanics. "The challenge is to prod an insect to fly, to have it do what it already knows how to do, and to intervene only when we want to intervene." Until now the researchers have been unable to meet this goal.
Do the insects suffer? "I don't know, and I don't know whether anyone knows for sure," says Ribak. "But the experiments which we conduct are extremely non-invasive. In comparison to experiments conducted on animals, this is child's play," he says. "The Helsinki agreements for experimentation on animals do not apply to insects. Insects are not regarded as important," says Weihs. "After the electrodes are implanted, we don't think there can be any pain, since the electric signal is a natural sign produced by the insect itself. We just tell the insect when it should make a movement, using these signals."