Summary of Cheap, ultra low-power light source runs on just 0.1 Watts
Tohoku University researchers created a low-cost, ultra-low-power flat panel light using carbon nanotube arrays. Consuming just 0.1 Watts, it rivals LEDs with higher efficiency and greener operation. The device functions similarly to cathode ray tubes by emitting electrons from nanotube tips onto a phosphor screen under vacuum.
Parts used in the Carbon Nanotube Light Source:
- Highly conductive carbon nanotubes
- Phosphor screen
- Cathode
- Organic solvent
- Surfactant compound
- Vacuum environment
Researchers at Tohoku University in Japan have developed a new low-cost flat panel light source that could pioneer a new generation of brighter, cheaper and greener lighting devices to rival LEDs. The device uses arrays of highly conductive carbon nanotubes to deliver evenly-distributed illumination with high efficiency and a power consumption as low as 0.1 Watts – about 100 times lower than that of light-emitting diodes.
LED lights are renowned for their high efficiencies, but the fact that only a fraction of the photons they produce actually ends up illuminating the surrounding environment suggests that there is still much room for improvement. One alternative approach explored by Prof. Norihiro Shimoi and colleagues was to build a structure based on carbon nanotubes, one-atom thick layers of carbon folded into a cylindrical shape.
This state-of-the-art device has a diode-like structure like LEDs but, curiously enough, the way in which it produces light is actually closer to the cathode ray tubes used in the TVs and computer monitors of the past century. Under the influence of a strong electric field, each carbon nanotube acts as a tiny cathode ray tube that releases a high-speed beam of electrons from its tip. These electrons then hit a phospor screen kept under vacuum and, in the process, release a small amount of energy that causes the phospor to glow.
Building the device was a fairly simple, low-cost process. The researchers started by mixing highly crystalline single-walled carbon nanotubes with an organic solvent and a surfactant compound. They then painted the mixture on the cathode and scratched the surface with sandpaper, which allows the electrons to more easily separate from the tip of the nanotubes.
For more detail: Cheap, ultra low-power light source runs on just 0.1 Watts
- How much power does the new light source consume?
The device consumes as low as 0.1 Watts. - What material is used to create the light-emitting structure?
Arrays of highly conductive single-walled carbon nanotubes are used. - Does the device operate like an LED or a CRT?
It operates closer to cathode ray tubes despite having a diode-like structure. - How are the electrons released from the nanotubes?
A strong electric field causes each nanotube tip to release a high-speed beam of electrons. - What happens when electrons hit the phosphor screen?
The impact releases energy that causes the phosphor to glow. - Is the manufacturing process considered complex or simple?
The building process is described as fairly simple and low-cost. - What components are mixed before painting the mixture on the cathode?
Researchers mix crystalline single-walled carbon nanotubes with an organic solvent and a surfactant compound. - Why was sandpaper used during the construction process?
Sandpaper scratches the surface to allow electrons to separate more easily from the nanotube tips.
