The rapid technological improvement in the semiconductor industry has enabled smaller and smaller devices to pervade our everyday lives. The real challenge in reducing the size to facilitate a ubiquitous integration of smart functions in any thing is drastically reducing the power consumption that constrains the volume to the presence of bulky batteries. An electronic device that dramatically reduces its power consumption can be powered by an alternative "green" source of energy such as light or vibration enabling the vision of the Internet of Things. In this scenario, the proposed research activity is intended to substantially enhance the energy efficiency of an IoT sensor node by a synergetic approach targeting both multisource harvesters and the System-on-Chip (SoC) design. The latter one aims in a comprehensive approach in which the macroblocks of different nature are designed exploiting at most an automated (digital) design flow. On this basis, a dramatic human-design effort reduction and silicon area for the same operation is expected for any SoC by a factor in the range of 10x-100x. This implies a faster time-to-market and a reduced cost of energy-autonomous Wireless Sensor Nodes. Challenging problems to be addressed are performance (i.e., resolution, speed). The effectiveness of the proposed approach will be verified and validated on demonstrators of industrial interest. The project targets to be innovative, interdisciplinary, and intersectoral across academies, an EU-based semiconductor company, and partners from MS and TC mostly based in the ASEN.