Intel's Ultrabook initiative might have been met with early skepticism, some of which still remains, but by and large, the light and powerful form factor is proving popular. It's also creating demand for small size components that can be squeezed into a pancake thin frame. As time goes on, expect to see Ultrabook models start to adopt 4mm micro fans that were originally developed for the handset market.
Citing sources entrenched in the cooling fan game, DigiTimes reports Acer's second generation Aspire S5 Ultrabook will rely on 4mm micro fans to keep its insides nice and chilly, or at least from burning up. Dell, Hewlett-Packard, Lenovo, and LG have all shown interest in using micro fans as well.
Those who develop cooling fans tell DigiTimes that 4mm is as thin as it gets with current technology, and while they were originally intended for handsets,4mm fans are a bit too loud for devices designed to sit up next a person's ear. That problem doesn't exist with Ultrabooks, which currently use 5.5mm or 7mm fans, depending on the model.
Switching to 4mm micro fans will drive up costs, though not by much. A typical fan used in today's Ultrabooks runs about $1.15 to $1.20, whereas 4mm micro fans can cost around $1.60 to $1.70.