Patent ID: 8430531

Claim:
A method for cooling at least one light emitting diode (LED) having a LED die that generates light and heat when electrical power is applied to the LED, the method comprising: arranging a heat exchange medium container with a wall arrangement including at least one wall having a thickness that extends between an exterior surface configuration and an interior surface configuration such that the interior surface configuration defines an inner cavity volume, the container also having an LED mounting area for mounting the LED to the exterior surface configuration of the container to transfer heat from the LED to a heat receiving portion of the interior surface configuration of the wall; at least partially filling the inner cavity volume with a magnetic fluid to at least cover the heat receiving portion of the interior surface of the wall with the magnetic fluid to receive heat from the LED, and selecting the magnetic fluid to be relatively more magnetic when at a relatively cooler temperature and relatively less magnetic when at a relatively hotter temperature, such that operating the LED causes the magnetic fluid proximate to the LED to heat to a temperature sufficient to cause the fluid to become relatively less magnetic; and positioning a magnetic field to circulate the magnetic fluid by magnetically attracting relatively cooler magnetic fluid toward the LED to push relatively hotter magnetic fluid heated by the LED away from the LED to remove heat from the LED during operation of the LED.