European researchers at Leuven, Belgium-based IMEC claimed to have achieved a new world record by building energy harvesters with an output power of 60µW.
The micromachined devices convert vibrational energy into electric power through an aluminium nitride (AlN) piezoelectric transducer.
Their high power rating is sufficient to drive simple wireless sensors that are required to intermittently transfer sensor readings, while their low resonance frequency of 500Hz makes them applicable to a range of applications such as tyre pressure or industrial equipment monitoring systems.
They are indispensable in situations where batteries cannot be used or replaced. Examples are autonomous sensor networks that are distributed over large areas and in locations that are difficult to access.
According to the researchers, the use of AlN as the piezoelectric material in the devices makes them easy to manufacture with existing CMOS processes, allowing them to be produced at a reasonable cost.