Whereas sensors sense and send, actuators act and activate. The actuator gets a signal and sets in motion what it needs to set in motion in order to act upon/within an environment.

In a sense you could say that an actuator does the opposite of a sensor and it’s at least as crucial, even if today what most companies do is acquiring and analyzing data, far less using data as triggers to make ‘something’ happen in the physical world where quite some value resides and not just in the scope of automation but also in consumer IoT applications.

Let’s make the usage of actuators more tangible from an IoT perspective:

An example was covered in our article on building management evolutions in the age of IoT and, simply put, goes like this: actuators sit on your radiator or control airflow in a smart room in a smart home or smart building; sensors detect there is no one in the room; actuators get triggered to lower temperature (or stop HVAC or whatever); control system reports back decision to management system (with energy savings as a result) and everyone happy.