Decades?
Cool, now it can die from tin whiskers before the battery does.
Atmel reckons it has crafted the world's lowest-power ARM Cortex-M microcontrollers, a family of chips that can go for "decades" on the same batteries. The SAM-L21 family is aimed at "fire alarms, healthcare, medical, wearable, and devices placed in rural, agriculture, offshore and other remote areas." Atmel says samples of …
Being able to run for decades from whatever battery Atmel had in mind when working out that it could run for decades from it is just one way of looking at things. Another way is to realise that the lower your power consumption gets, the smaller your power source needs to be to maintain the same runtime, which may open the door to power sources other than a battery...
Still, given that Li-ion was invented merely ~24 years ago, we might be surprised. I have one last Panasonic CGR18650HM that I pulled from a worn-out Thinkpad 600E pack roughly a decade ago, and while left in a box for more than a few years, it kept a proper voltage. Today it still charges and runs an MP3 player. On the other hand, it was apparently made in Japan as opposed to China. YMMV
I was thinking something similar when someone above mentioned radiators. They may be the lowest-power chips yet, but I guess we're not going to see these powered by thermopiles especially if they're an active part of a thermostat system.
The other thought that struck me was the ROTM angle. It's a little bit frightening that they now have the capability of running in "sleeper cell" mode for decades, just biding their time waiting ... waiting ...