Nanowires. Is There Anything They Can't Do?
The University of Illinois at Urbana Champaign is a hotbed of high-tech research these days. They've recently demonstrated a process for "growing" upright copper nanowires on surfaces made from a wide array of materials. These nanowires could be used to make Field-Emission Displays, brighter and sharper than existing flat panel displays, by using the nanowires to shoot electrons at phosphor particles on a screen.
The copper nanowires are suitable for use in FEDs because they are uniform and have a very pointed tip. "The smaller the tip size the stronger the electric field," Kim says. "That is why even with a very small voltage...they will become very efficient electron emitters." The nanowires emit electrons at low voltages of 100 Volt, unlike the tungsten filament used in conventional, bulky cathode-ray-tube televisions (CRTs), which require many kilovolts.
Field-emission displays promise to be less power-hungry than plasma screens and liquid crystal displays, while keeping a CRTs brightness and sharpness. They work on a similar principle as CRTs, but are only a few millimeters thick. Instead of using a single electron gun, they use millions of tiny electron emitters to shoot electrons at red, green and blue phosphors coated on a screen.
There are challenges to making the nanowires robust enough to last for the normal useful life of a TV - about ten years. And the required vacuum between the emitters and the screen would make them more delicate than your average display. But the end result would be brilliant to look at, and energy efficient too. More than you could say for most of the programing on TV
The copper nanowires are suitable for use in FEDs because they are uniform and have a very pointed tip. "The smaller the tip size the stronger the electric field," Kim says. "That is why even with a very small voltage...they will become very efficient electron emitters." The nanowires emit electrons at low voltages of 100 Volt, unlike the tungsten filament used in conventional, bulky cathode-ray-tube televisions (CRTs), which require many kilovolts.
Field-emission displays promise to be less power-hungry than plasma screens and liquid crystal displays, while keeping a CRTs brightness and sharpness. They work on a similar principle as CRTs, but are only a few millimeters thick. Instead of using a single electron gun, they use millions of tiny electron emitters to shoot electrons at red, green and blue phosphors coated on a screen.
There are challenges to making the nanowires robust enough to last for the normal useful life of a TV - about ten years. And the required vacuum between the emitters and the screen would make them more delicate than your average display. But the end result would be brilliant to look at, and energy efficient too. More than you could say for most of the programing on TV
