There are two types of devices: low-power and high-power.
Caesium vapor thermionic generators are low-power devices that convert heat energy to electrical energy.
This is particularly important for deeply embedded audio applications running on low-power mobile devices.
Bluetooth Low Energy is to be used for low-power mobile devices.
Nearly all low-power devices use non-Windows operating systems for this reason.
It is not yet ready to run on desktop computers, much less low-power mobile devices like cell phones.
Zinc-air cells alone are perfect for low-power, steady-drain devices.
The target will be tablets and other battery-operated, low-power devices.
But the peculiar needs of extremely low-power devices, like phones, can work against even the most option-rich market.
This is in strong contrast with the much lower energy consumption of CPUs designed for low-power devices.