There is an increasingly stronger interaction between microelectronics, applications, and new megatrends in our society: demographic changes (urbanization, health care), sustainability (resource and energy management) and digitalization (from miniaturization over the IoT towards ‘big data’). This talk will discuss the role of microelectronic sensor circuits and systems in solving critical issues related to those megatrends. After an introduction into those problems, I will show both examples for sensor and for circuit technologies enabling these applications. To have impact onto the society such electronic systems however are not good enough yet: sensor system data need evaluation in the application context to be useful to the society. In especially, if artificial intelligence shall support such usefulness this learning is a mandatory step for the usefulness. Finally, I will discuss simple artificial intelligence algorithms, as well as how to make use of them not only in the application context, but also to enhance the performance of sensor systems.