Can a surveillance drone be made virtually invisible? VeraTech, based in Minnesota, US, thinks so. And patent applications filed by the company explain how.
"Persistence of vision" turns the fast-moving rotors of any helicopter into a near-transparent blur, while the slow-moving body looks solid. Inventor Michael Dammar has come up with a way of making the whole body of an aircraft spin as it flies, turning it into a single blur in the sky. This would not evade radar but should help the aircraft avoid visual identification.
The so-called Phantom Sentinel aircraft is Y-shaped, consisting of a single long wing attached to two short aerodynamic extensions which each end in a propeller. And the weight is carefully balanced so that the centre of mass is positioned between the two extensions. When the motors are running, the solid part of the aircraft spins around this centre of mass, and the longer wing generates lift. The whole thing moves so fast that persistence of vision turns it into a single blur.
Making the plane sky blue, or largely transparent, should help conceal it further, Dammar claims. He adds that a camera can be placed near the centre of mass and used to build a panoramic picture of the ground below, after software processing.
The companyâ€™s website has streaming video footage of early prototypes in flight
Read the full invisible drone patent application
The idea of wearable computing is appealing. A head-mounted display can show information processed by a small portable computer while speech-recognition software can replace keyboard typing. But how do you move a cursor without a holding a mouse?
Simply move those feet, say three researchers working for Hewlett Packard in the UK. A magnetic sensor can be attached to one foot and a transmitter emitting pulsed magnetic signals clipped onto the other one. As the sensor foot is moved around it continually calculates its position relative to the other foot, using these magnetic pulses.
So, moving each foot can correspond to movements of a cursor on the head-mounted display. Foot-twisting can be used for right or left mouse clicks and sliding one foot over the ground can be translated into dragging and dropping. This would allow someone to use a wearable computer while keeping their hands free for other tasks.
Read the full hot-foot computing patent application
Threading a cable through the chassis of a car, boat or plane can be tricky. Sharp metal edges can cut the cable insulation, shorting power and even starting a fire.
Researchers at the University of Vermont, US, have been working with NASA on a type of cable insulation that heals itself when breached. The healed section also adds a protective layer against further damage in future.
The central live wire within the cable is surrounded by a layer of insulation laced with a soft resin. Glue hardener is also sealed inside microcapsules that are dispersed within the insulation layer.
Under normal circumstances the microcapsules keep the hardener away from the resin, so the cable remains soft and easy to thread. But if the cable insulation is chafed or breached, the microcapsules break open to release the hardener. This heals the insulation and adds a solid section that should prevent further damage.