Periodic Reporting for period 3 - OXiNEMS (Oxide Nanoelectromechanical Systems for Ultrasensitive and Robust Sensing of Biomagnetic Fields)
Berichtszeitraum: 2021-11-01 bis 2024-01-31
The OXiNEMS project focused on the development of new types of micro&nanoelectromechanical devices using transition metal oxides. Current technology for Microelectromechanical Systems (MEMS) and Nanoelectromechanical Systems (NEMS) is mainly based on silicon and related materials, but future M/NEMS are expected to integrate new functionalities far beyond the capabilities of conventional semiconductors. Full-oxides NEMS technology - or oxide nanomechanics - will take advantage from a rich spectrum of physical properties such as ferromagnetism, magnetoelectricity, electro-optical effects, multiferroicity, superconductivity, structural phase transitions, only to cite some of the phenomena of these materials.
Our science-to-technology breakthrough has been targeting a proof-of-concept ultrasensitive oxide-based NEMS device for the detection of biomagnetic fields generated by biological tissues. The OXiNEMS team worked on an ultrasensitive magnetometer able to measure very weak magnetic fields, targeting those generated by human brain activity, of the order of tens of femtotesla. Differently from currently employed SQUIDs, thanks to their sensitivity and robustness to strong static and pulsed applied fields, the OXiNEMS sensors are foreseen to allow the effective integration of MEG with other imaging techniques improving the MEG resolution, such as ultralow field (ULF) Magnetic Resonance Imaging (MRI) and with techniques traditionally non-compatible with MEG, such as Transcranial Magnetic Stimulation (TMS).
Our science-to-technology breakthrough has been targeting a proof-of-concept ultrasensitive oxide-based NEMS device for the detection of biomagnetic fields generated by biological tissues. The OXiNEMS team worked on an ultrasensitive magnetometer able to measure very weak magnetic fields, targeting those generated by human brain activity, of the order of tens of femtotesla. Differently from currently employed SQUIDs, thanks to their sensitivity and robustness to strong static and pulsed applied fields, the OXiNEMS sensors are foreseen to allow the effective integration of MEG with other imaging techniques improving the MEG resolution, such as ultralow field (ULF) Magnetic Resonance Imaging (MRI) and with techniques traditionally non-compatible with MEG, such as Transcranial Magnetic Stimulation (TMS).
The OXiNEMS team investigated the fabrication processes for M/NEMS based on transition metal oxide thin films. We realized new typologies of M/NEMS structures with different oxides such as (La,Sr)MnO3 (a well-known magnetic oxide), LaAlO3 (a high-permittivity dielectric), EuTiO3 (a dielectric with anti-ferromagnetic transition at 5.3 K and studied for its incipient ferro-electricity). We made systematic and deep characterizations of the mechanical properties of cantilevers, freestanding trampolines and microbridges under different measurement conditions and temperatures, enlarging the comprehensions of the advantages and limits of epitaxial oxides for the realization of new micro&nanomechanical sensors and actuators. The race toward the realization of a full-oxide magnetometer (hybrid sensor) has focused our research on several original aspects in the microfabrication of complex freestanding structures made with oxide heterostructures.
At some stage of the project we decided to realize a preliminary basic structure. This prototype integrates an YBCO superconducting micro-patterned thin film circuit with a magnetic resonator made of a silicon nitride freestanding trampoline combined with a cobalt magnetic layer. The operation of the hybrid sensor is based on nanomechanical sensing: the external magnetic field determines the amount of current flowing through the superconducting circuit and then the value of the mechanical resonance of coupled magnetic trampoline. The mechanical resonances of the trampoline resonator are probed using a focused laser beam (optomechanical detection). The OXiNEMS project realized five optomechanical setups with different purposes and installed at different venues (CNR, University of Hamburg, University Gabriele d’Annunzio (UdA) and Quantified Air B.V. (QA). As the hybrid sensors are expected to work in real environment and be integrated in a future magnetoencephalographic system, UdA and QA developed the instrumentation to integrate the sensor into a channel working inside a magnetically shielded environment. This biomagnetic channel comprises the sensor, the scalable interferometer and the custom cryogenic system that will be placed near the human skull for the detection of the biomagnetic field. Our research activities generated scientific knowledge and original results and at the same time developed technological solutions with different technology readiness levels paving the way to new products and processes together with concrete perspectives for future collaborative projects.
In collaboration with the Exploitation Partner (META), we, the project partners, identified and assessed a select set of Key Exploitable Results (KERs). We evaluated their maturity, market potential, value propositions, existing competition, and mapped out pathways for their future exploitation. To maximize the impact of each KER, partners engaged various stakeholder groups through targeted dissemination activities, including presentations at 28 international conferences, publications in 7 journals, and educational outreach. Additionally, KERs were communicated to the general public through five events at the Genoa Science Festival and European Researchers’ Night, alongside dedicated outreach webpages on the project website. The field of oxide nanomechanics has also been promoted with the organization of an open online school on this topic on November 8th, 2023. An online workshop on “Materials and Devices for Biomagnetism and Magnetometry” has been organized on April 16th, 2024.
Two invention patents conceived within the project have been granted while a third patent application arising from OXiNEMS has been recently filed. Our project website (www.oxinems.eu) contains all the information related to the dissemination and communication actions.
At some stage of the project we decided to realize a preliminary basic structure. This prototype integrates an YBCO superconducting micro-patterned thin film circuit with a magnetic resonator made of a silicon nitride freestanding trampoline combined with a cobalt magnetic layer. The operation of the hybrid sensor is based on nanomechanical sensing: the external magnetic field determines the amount of current flowing through the superconducting circuit and then the value of the mechanical resonance of coupled magnetic trampoline. The mechanical resonances of the trampoline resonator are probed using a focused laser beam (optomechanical detection). The OXiNEMS project realized five optomechanical setups with different purposes and installed at different venues (CNR, University of Hamburg, University Gabriele d’Annunzio (UdA) and Quantified Air B.V. (QA). As the hybrid sensors are expected to work in real environment and be integrated in a future magnetoencephalographic system, UdA and QA developed the instrumentation to integrate the sensor into a channel working inside a magnetically shielded environment. This biomagnetic channel comprises the sensor, the scalable interferometer and the custom cryogenic system that will be placed near the human skull for the detection of the biomagnetic field. Our research activities generated scientific knowledge and original results and at the same time developed technological solutions with different technology readiness levels paving the way to new products and processes together with concrete perspectives for future collaborative projects.
In collaboration with the Exploitation Partner (META), we, the project partners, identified and assessed a select set of Key Exploitable Results (KERs). We evaluated their maturity, market potential, value propositions, existing competition, and mapped out pathways for their future exploitation. To maximize the impact of each KER, partners engaged various stakeholder groups through targeted dissemination activities, including presentations at 28 international conferences, publications in 7 journals, and educational outreach. Additionally, KERs were communicated to the general public through five events at the Genoa Science Festival and European Researchers’ Night, alongside dedicated outreach webpages on the project website. The field of oxide nanomechanics has also been promoted with the organization of an open online school on this topic on November 8th, 2023. An online workshop on “Materials and Devices for Biomagnetism and Magnetometry” has been organized on April 16th, 2024.
Two invention patents conceived within the project have been granted while a third patent application arising from OXiNEMS has been recently filed. Our project website (www.oxinems.eu) contains all the information related to the dissemination and communication actions.
The OXiNEMS project has boosted the field of oxide nanomechanics by employing new oxide materials, new micromachining techniques, and deploying new characterization tools, while increasing the quality, and the complexity of the freestanding oxide structures produced thus far. These developments exhibit an analogy with silicon (nitride) M/NEMS: OXiNEMS contributed to the foundation of the field of oxide M/NEMS, similarly with what has been done decades ago for MEMS made with the traditional semiconductor materials. Multifunctional oxides may serve as a platform for the development of future sensors and actuators, in which the unique properties of metal oxides are coupled with the mechanical domain. The OXiNEMS project has focused on the application of oxide MEMS to robust yet highly sensitive magnetometry. Building blocks for the implementation of the disruptive idea of integrating nanomechanical sensing, optomechanics and biomagnetism have been realized, and such a system would enable the implementation of novel multimodal imaging techniques, which cannot be implemented with existing technology. Future engineering of the hybrid sensor, to be implemented in a multi-channel imaging apparatus, will impact on the field of biomagnetism, improving information on human brain functioning with consequent clinical and scientific outcomes. The optomechanical solutions we developed for the biomagnetic channel had impact also in other fields, where robust and scalable interferometric readout is a benefit. An exploitable result based on the OXiNEMS concepts has been also a silicon MEMS magnetometer architecture with integrated magnetic elements and room temperature operation. This device could allow e-compass producers to decrease the costs for production and increase the products' (like drones) performances.