Graphite foam technology developed by James Klett of Oak Ridge National Laboratory's Materials Science and Technology Division extends the life of light-emitting diode lamps and has been licensed to LED North America (Oak Ridge, TN).
The company intends to use the graphite foam to passively cool components in LED lamps, which are increasingly in demand in applications such as street lights and parking garage lighting. LED North America specializes in providing LED lighting products for municipal, commercial, and industrial applications.
Cooling LED lamps is critical to increasing their efficiency, considering that each 10-degree decrease in temperature can double the life of the lighting components. Using graphite foam to more efficiently manage the heat of LEDs could help extend the lamp's lifespan and lower its price, making the lamps more attractive to a broader consumer base. James Klett hopes the graphite foam can offer potential savings for customers.
"While this technology will reduce temperatures and increase the life of the LED lighting systems, what it will really do is save municipalities millions of dollars every year in replacement fixture costs as well as maintenance," Klett said.
The newly licensed graphite foam invention offers many advantages over comparable heat sink materials such as copper and aluminum. Graphite foam's high thermal conductivity, low weight, and easy machinability give the material greater design flexibility and make it a lighter, cheaper, and more efficient cooling option.
The foam's unusual graphite crystal structure is the key to its conductivity. It has a skeletal structure full of air pockets, making it only 25 percent dense and lightweight. The network of ligaments in the foam wicks heat away from its source, making it an excellent candidate to cool the LED lamp components.