Wireless sensors nodes are devices that measure a response to a change in a physical condition like temperature and pressure. The applications for wireless sensors are many and varied and include habitat monitoring, object tracking, nuclear reactor control, fire detection, and traffic monitoring. In a typical application, a wireless sensor network is scattered in a region where it is meant to collect data through its sensor nodes.

Wireless sensors are typically equipped with a radio transceiver, a small microcontroller, and an energy source, usually a battery. For wireless sensor applications with a constant heat source, the power output of the TEG needs to match or exceed the power input requirements of the sensor. If the heat source is variable, the TEG can be used to trickle charge a battery that powers the sensor directly.