Advanced Heatsinks are a further development of Inner Sphere heatsinks.
Inner Sphere Heat sinks are made of a number of materials. Traditional heat sinks, the so-called single strength heat sinks, typically use radiators made of very thermally conductive oriented graphite (which may have up to five times the thermal conductivity of copper).
The actual coolant circulating in the heat sink varies from manufacturer to manufacturer and military to military. Heavy oils (hydrocarbon and silicone) are favored for their high boiling points and thus may be contained by low pressure tubing. Water-based coolants, typically modified with glycols, have nearly unbeatable heat capacities and are readily available for resupply. Freons work very effectively with the heat pumps in heat sinks. Some gases, like helium, also find use in heat sinks. Contrary to what might be thought, liquid nitrogen is a very poor coolant - it has very little heat capacity and boils far too easily.
Advanced Heatsinks improve on the general design by utilizing modern Fabricator technology to replace several of the materials, such as the graphene with modern meta materials that have a much higher thermal conductivity. Additionally graphene reinforced materials allow to contain the two main collants of glycol modified water and liquid lithium, the latter used to cool fusion reactors.
Compared to Inner Sphere Heatsinks, Advanced Heatsinks are 90 percent more effective at the same weight and the same volume.