What is it with former Microsoft executives and mosquitos? At last year's TED conference, Bill Gates unleashed a jar of live mosquitos during his talk in order to make a point about the problems of malaria. This year, it was former Microsoft CTO Nathan Myhrvold who was on stage demonstrating his plan to use lasers to shoot mosquitos out of the sky as part a malaria-eradication project. Myhrvold too had live mosquitos on stage, though they were contained in glass and because of that the bugs weren't killed when the laser was used.

As we've reported in the past, Myhrvold certainly likes to think outside the box -- including unique approaches to preventing hurricanes and cooling the planet. Will his plan to wipe out malaria actually work?

Here's a description of the technology from a research paper by Intellectual Ventures, the Bellevue firm run by Myhrvold.

A completely novel invention from IV, called a photonic fence, uses a combination of cameras and lasers to detect mosquitoes at a distance and to shoot them down while they fly. Although this approach may sound high-tech (and indeed some of the inventors are veterans of the antiballistic missile program), the basic components needed for such a system largely exist already in inexpensive consumer electronics, such as laser printers, Blu-ray disc writers, camcorders, and video game consoles. The working prototype at IV Lab was constructed almost entirely from parts purchased second-hand on eBay and similar websites.

The system would create a virtual fence made out of light -- we call it a “photonic fence.” Light Emitting Diodes (LED) lamps on each fence post would beam light at adjacent fence posts up to 100 feet (30 meters) away; the light would then hit strips of retroreflective material (similar to that used on highway signs) and bounce straight back toward the illuminator. A camera on each fence post monitors the reflected light for shadows cast by a hapless insect flying through the vertical plane of light.

When an invading insect is detected, software developed at IV Lab identifies it by training a nonlethal laser beam on the bug and using that illumination to estimate the insect’s size and also to measure how fast its wings are beating. Using this method, the system can not only distinguish among mosquitoes, butterflies, and bumblebees, but it can even determine whether a mosquito is male or female (Females are significantly larger than males and have slower wingbeats.) This is useful because only female mosquitoes bite humans.

You can see a video of the technology at work at Intellectual Ventures Lab, while blogger Robert Scoble caught up with Myhrvold for a short interview after the demo.