In this project, we develop a new class of nanoelectromechanical systems (NEMS) based on integrated multifunctional oxides. With these devices, we will construct ultrasensitive and robust detectors for biomagnetism and apply them as transducers for applications in the field of human brain imaging. OXiNEMS will exploit advanced multifunctional materials, namely transition metal oxides (TMOs) to create new types of NEMS and MEMS devices based on crystalline heterostructures and revolutionize the field of M/NEMS across many areas of technology. As proof-of-concept of this innovative vision, OXiNEMS targets breakthrough research for developing nanomechanical sensors for measuring weak magnetic fields, in particular those found in Magnetoencephalography (MEG) and Ultralow-Field/Very-Low-Field (ULF/VLF) Magnetic Resonance Imaging (MRI). Presently available instruments are based on Low Temperature SQUID detectors which are extremely sensitive, but are mildly robust to static and pulsed magnetic fields, such as the ones used in ULF/VLF MRI and Transcranial Magnetic Stimulation (TMS), still not integrated with MEG. SQUIDs require expensive operation and maintenance costs, as they work in a liquid helium (4K) bath. OXiNEMS will develop robust magnetic field sensors based on nanomechanical resonators with all-optical readout, working in a simplified cryogenics setup at the liquid nitrogen temperature (77K). This allows for a much smaller working distance which enables biomagnetic detection with unprecedented spatial resolution. The success of OXiNEMS will thus both revolutionize the NEMS and MEMS field by introducing a new class of multifunctional sensors/actuators, and also it will open new directions in the field of human brain imaging by facing one of the most critical current challenges of neuroscience and the clinical community: to image brain activity and connectivity with high spatial and temporal resolution combining MEG with MRI and TMS on the same system.