Triple-standard disc

The electronics industry is in a fine mess, with two blue-laser disc standards (Blu-ray and HD-DVD) competing to succeed ordinary red-laser DVDs.

On 26 September, Warner will be the first studio to release a movie, Lake House, on all three disc standards simultaneously.

Meanwhile, however, two top Warner engineers, Alan Bell and Lewis Ostrover, have been working on a cheaper and more elegant solution.

Blu-ray uses a 405-nanometre wavelength laser to read data from tracks 0.1-millimetres-deep on the top surface of a disc. HD-DVD, on the other hand, uses the same wavelength to read recordings at a depth of 0.6 mm.

Warner’s plan is to create a disc with a Blu-ray top layer that works like a two-way mirror. This should reflect just enough blue light for a Blu-ray player to read it okay. But it should also let enough light through for HD-DVD players to ignore the Blu-ray recording and find a second HD-DVD layer beneath.

An ordinary DVD recording could be put on the other side, so that conventional DVD players can read the disc as well.

Although the triple-standard disc will cost more to make, it should still be cheaper than pressing three, and shops should be pleased not to have their shelves overloaded with so many different discs.

Read the full blue laser hybrid patent application.

The "bad hair day" brush

Thanks to Japan's Kao Corporation you may soon be able to rate a "bad hair day" on a scale of 1 to 10. The company is developing a smart hairbrush, which can quantify the damage caused by treatments such as hair dyes and bleaches.

The hairbrush analyses sound as hair is brushed. This reveals a surprising amount about the state of the hair, according to five inventors from the company.

To make the brush, an aluminium bar a few micrometers long is polished and sandblasted and then buried amongst the prongs of the brush. A microphone attached to the bar then picks up vibrations as hair is dragged over the bar. A built-in strain gauge also records the resistance caused by brushing.

A USB connection feeds these measurements to a PC which compares the sound and the pulling strain. Tests carried out in a Tokyo hair salon showed that hair in good condition makes far less noise than dirty hair with split ends. Loud sound at high frequencies also indicates too much bleaching, the inventors say. The brush could help hairdressers work out the appropriate treatment for a person in their care.

Read the full damage-sensing hairbrush patent application.

Enzyme sensor

Intel has plans to move into medicine. A patent application from the world's biggest microchip-maker reveals a method for using tried-and-tested silicon fabrication techniques to mass produce low cost biosensors for home or hospital use. Putting many sensors on a single chip should reduce the power needed to drive such a device.

To make the biosensors, identical pairs of piezoelectric electrodes are deposited on a silicon wafer and some of the silicon beneath each electrode is etched away to create an identical pair of resonant cavities. When a current is passed through the electrodes, they vibrate with identical resonance.

An enzyme such as glucose oxidase is then attached to one of the two electrodes. When the chip is exposed to blood sugar, this binds with the enzyme making the electrode underneath heavier. The two electrodes then vibrate differently, which an on-chip sensor can easily detect. And comparing its resonance to a stored database provides a quick blood-sugar reading.

If the electrodes are coated with antibodies or DNA instead of enzymes, the chip could also provide early warning of an infection.

Read the full enzyme sensor patent application.

For more than 30 years, Barry Fox has trawled through the world's weird and wonderful patent applications, uncovering the most exciting, bizarre or even terrifying new ideas. Read previous Invention columns, including:

Ultimate body armour, long-range stunner, tongue-o-vision, jellyfish injections, Flesh-burn sensor, fire-escape tubes, VoIP mangling, in-flight rearming, sense that fat, Designer speakers, throw-away parachutes, password-protected bullets, spinning touchdown, palmtop Feng Shui, Origami gadgets, mile-high showers, Hydrogen fuel balls, human cannonballs, the riot slimer, the bomb jammer, Apple's all-seeing screen, the TV-advert enforcer, the wing-sprouting drone, the drink-driver arm scanner, laser spark plugs, remote-controlled implants,the "I've been shot" gun, the snore zapper, the guitar phone, explosive-eating fungus, viper vision, exploding ink, the moody media player, the spy-diver killer, preventing in-flight interference, the inkjet-printer pen, sonic watermarks, the McDownload, hot-air plane, landmine arrows, soldiers obeying odours, coffee beer, wall-beating bugging, eyeball electronics, phone jolts, personal crash alarm, talking tooth, shark shocker, midnight call-foiler, burning bullets, a music lover's dream, magic wand for gamers, the phantom car, phone-bomb hijacking, shocking airport scans, old tyres to printer ink and eye-tracking displays.