This site has been following Nanocomp Technologies which makes sheets of carbon nanotubes. Nanocomp Technologies had 3X6 foot sheets back in early 2008. Then in early 2009, they announced that they had 4X8 foot sheets. So close to double the square footage of the 16 square foot sheets at 32.
In a single process, they have integrated the continuous growth Of Carbon Nanotubes (CNTs) and the formation of functional products (sheets of carbon nanotubes).
Volume of Production and Properties of the Bulk Sheets
* Nanocomp Technology is making hundreds of square feet of sheets each week. They are scaling up to tons of material in sheets next year (2012)
* the 3X6 and 4X8 foot sheets can and are being bonded together with a little overlap to make larger sheets for different applications
* Other companies are producing more carbon nanotubes but those are primarily only carbon nanotubes that are so short that the material is like powder
* The electrical properties of the sheets are already superior to existing materials by weigth for applications ilke radiation and electromagnetic shielding
* They can achieve the same electromagnetic shielding at one third to one half of the weight of traditional material (copper wires)
* Superior electrical properties already exist for antennas
* Nanocomp has developed the capability to tune multiple properties in their carbon nanotube sheets. Multiple functions can be addressed at the same time with this capability.
High Strength – spun conductive yarns exhibit breaking strengths up to 3 GPa expressed or in other terms: 1.5 Nt/Tex or 450,000 psi and with fracture toughness that is higher than aramids (such as Kevlar or Twaron). CNT sheets have breaking strengths, without binders, that range from 500 MPa to 1.2 GPa depending upon tube orientation. Aluminum breaks at 500 MPa, carbon steel breaks around 1 GPa.
Electrical Conductivity – Capable of carrying more current than copper and are also more conductive than copper at high frequencies.
Thermal Conductivity – Capability to transfer more heat than copper or silver on a
per weight basis.
Thermoelectric behavior – Demonstrate a Seebeck coefficient of greater than 60 µV/ºK
and power greater than 1 watt/gram.
Extremely Lightweight – Less than half the weight of aluminum
The outside of the current Nanocomp furnace. Production facilities are being scaled up from 11,000 square feet to 40,000 square feet (next year/2010) and then to 100,000 square feet (a few years out).
Windle’s Carbon Nanotubes versus Nanocomps
In Cambridge, Prof Windle is making carbon nanotubes that are several centimeters long and several times stronger than the Nanocomp carbon nanotubes. Nanocomp has been able to make a 40 centimeter long carbon nanotube as well but is focusing on what can be built in higher volume with a cost of $100/kg or less. The research on longer and stronger carbon nanotubes is vital but there will be the delay while high volume and reasonable cost production is achieved with stronger and longer carbon nanotubes.
Similarly other properties can be enhanced to higher levels in tiny quantities but industrial levels need high volume and reasonable cost.
Applications and Benefits of the Sheets and As Production Scales Up
* The production that Nanocomp is planning to achieve over three years would be enough to retrofit all of the EMI shielding in all commercial jets.
* 787 would save 2000 lbs using the Nanocomp CNT product for EMI shielding. This would save the airline money with lower fuel costs
* 200 lbs of weight could be saved in a typical satellite. Currently it costs $20,000-100,000 per pound to launch a satellite into geosynchronous orbit. Therefore, $4-20 million in launch cost savings for each launch.
* Alternatively or in combination superior EMI shielding could be employed at lower or equal weight.
DIY e-bombs could bring down current commercial aircraft, but superior shielding could prevent that vulnerability and shield from lightning strikes and allow passengers to use electrical devices like cellphones and wireless communication.
* the material is still ten times inferior to copper for the power grid in terms of ohm centimeters. Plus the cost is too high for the CNT and production is way too low.
* Where wires and cables need high frequency characteristics or other electrical and heat properties in lower volume (a few tons per year now and a few hundred tons per year in 5-10 years) then these CNT sheets should be superior.
* Other space applications that are being investigated are carbon nanotube solar sails and electric solar sail wiring