The Hybrid Optomechanical Technologies (HOT) consortium will lay the foundation for a new generation of devices, which connect, or indeed contain, several platforms at the nanoscale in a single “hybrid” system. As hybrid interfaces, they will harness the unique advantages of each subsystem within a nano-scale footprint, while as integrated hybrid devices they will enable entirely novel functionalities. A particular focus will be on nano-optomechanical devices that comprise electrical, microwave or optical systems with micro- and nano-mechanical systems. Research in the past decade, in particular by European groups, has shown the significant technological potential that such nano-optomechanical systems can offer, in particular by establishing a new way in which optical, radio-frequency and microwave signals can be interfaced. The present consortium will explore the potential of these hybrid nano-optomechanical systems; in particular, hybrid opto and electro-mechanical devices operating at the physical limit for conversion, synthesis, processing, sensing and measurement of EM fields, comprising radio, microwave frequencies to the terahertz domain.