Harvard team develops robotic insect - Robobee

A robotic fly with a body only as tall as a penny standing on edge has, passed its flight tests with flying colors. The so called Robobee, is the smallest artificial insect yet flown, according to the team that built it.

The robotic fly lifts off the table, hovers, and flies in different directions and at this stage in its evolution, it is still tethered by thin wires that allow its designers to power and guide it. Landing however, remains an issue.

According to the team that developed it, it was the first such object to fly in a controlled manner and represented a key step in developing insect-size drones that designers say could one day search collapsed buildings for survivors following a disaster, sample an environment for hazardous chemicals before humans are sent in, and even accurately locate enemy soldiers or terrorists holed up in urban areas.

Insect flight has intrigued researchers over the years, largely as it appears to violate all principles that keep birds or airlines in the air.

RoboBee , though is something of a misnomer given that it was modelled after a hoverfly, which looks like a bee. Hoverflies are able to control their movements remarkably well from hovering, as the name implies, to lightly touching down on a wind-tossed blossom.

The mechanical hoverfly, built by researchers and graduate students at Harvard University, weighs a meagre .003 ounces, with its wingspan stretching over an inch and wings flapping up to 120 times a second.  Each stroke covers an angle of 110 degrees – all comparable to a hoverfly's characteristics and the wings weigh around .00003 of an ounce.

The latest arrival in the line of mini-drones, quadcopters and such devices owes its existence to a new fabrication process based on the principle of pop-up books but it would not be available in stores any time soon.

It takes two days to build a single RoboBee, and the tiny device has to be supplied power and guidance to its flight through tethers.

According to experts, getting all the sensors and power on board was many years out, but the new tiny craft was an definite advance.

What is perhaps the biggest impediment to building tiny artificial insects is that, researchers do not even have a good enough understanding yet of how aerodynamic principles change on such small scales, they are therefore not able to precisely predict how delicate wing movements would alter flight.

Mechanical engineer, Robert Wood now at Harvard University, though decided 12 years back, to take on the challenge of building an insect-sized robot- partly to understand the flight mechanics of small flapping wings and partly, ''because it was so hard.''

According to experts, not connected with the work, the method that Wood and his colleagues developed to make microrobots with movable parts was impressive in its own right, and had applications well beyond the specific structures they were building, and could even lead to new kinds of medical devices.