Smartphones are some of the most reliable pieces of consumer tech out there, but they do have an “Achilles’ heel”, and it’s temperature extremes. For anyone who has tried to use a smartphone in extremely cold or very hot conditions, performance hiccups and reluctance to respond to user input are commonplace. The source of the problem is the lithium-ion batteries which can’t supply enough power when stressed by temperatures that reach either edge of their operational spectrum.
A team of engineers at Purdue University claim to have developed a solution for this problem, calling their creation a “thermal switch” for smartphones, and promising that it’ll bring unprecedented stability under any weather condition. What they did was to create a dynamically adjusting compressible graphene foam that engulfs the internal electronic components and the cell of the smartphone, sitting between them and the outer shell/casing.
The foam follows a physical expansion and contraction for a thickness of 0.2 mm and up to 1.2 mm. The capability to adjust is crucial, as otherwise, a device that would be safe from the freezing cold in Canada would be unsuitable for use in a hot Californian summer, etc. As such, the thermal switch needs to operate both as an insulator and as a conductor, depending on the user’s needs. For example, when the thickness goes down to 0.2 mm and the foam is fully compacted, the thermal conductance goes up by a factor of 8. If the Purdue University team manages to convince smartphone vendors of the usefulness of their “thermal switch”, it will be interesting to see what implementations will emerge and which market groups will be targeted. Possibly, this thermal switch foam would be ideal for rugged devices that promise ultimate reliability even in the harshest of use-cases. For the rest, “lighter” and thinner films could be incorporated to improve battery life and reduce heat-induced degradation.