Periodic Reporting for period 1 - FlexiMMG (Flexible Sensors for portable Magnetomyography: Envisaging innovation and Unveiling opportunities)
Reporting period: 2023-10-01 to 2025-09-30
The Flexi-MMG project addresses the growing need for non-invasive, portable tools to monitor human muscle activity in real-time, particularly for applications in healthcare, rehabilitation, and human-machine interfaces. Traditional methods like electromyography (EMG) rely on electrical signals from muscles, but they suffer from limitations such as poor spatial resolution, susceptibility to motion artifacts, and inability to detect deep muscle signals. Magnetomyography (MMG), which measures the weak magnetic fields generated by muscle contractions (typically in the pico- to nano-Tesla range), offers a promising alternative due to its non-contact nature, high sensitivity to deep tissues, and immunity to electrical noise.
The overall objectives of Flexi-MMG were to develop flexible planar Hall effect (PHE) magnetic sensors optimized for portable MMG applications. These sensors aim to achieve sub-nanoTesla resolution in low-frequency regimes (<20 Hz) through advanced noise analysis and material engineering. The project pathway to impact includes validating these sensors in biomagnetic setups, exploring translational uses in Internet of Things (IoT) devices and sustainable healthcare, and fostering interdisciplinary collaborations. By integrating flexible magnetoelectronics with biomedical engineering, Flex-MMG contributes to tackling challenges in neuromuscular disorder diagnostics, prosthetic control, and elderly care. Expected impacts include scalable, low-cost wearable devices that could benefit millions affected by muscle-related conditions, aligning with EU priorities in digital health and sustainable innovation. The project's scale is significant, potentially reducing healthcare costs by enabling remote monitoring and early intervention.
The overall objectives of Flexi-MMG were to develop flexible planar Hall effect (PHE) magnetic sensors optimized for portable MMG applications. These sensors aim to achieve sub-nanoTesla resolution in low-frequency regimes (<20 Hz) through advanced noise analysis and material engineering. The project pathway to impact includes validating these sensors in biomagnetic setups, exploring translational uses in Internet of Things (IoT) devices and sustainable healthcare, and fostering interdisciplinary collaborations. By integrating flexible magnetoelectronics with biomedical engineering, Flex-MMG contributes to tackling challenges in neuromuscular disorder diagnostics, prosthetic control, and elderly care. Expected impacts include scalable, low-cost wearable devices that could benefit millions affected by muscle-related conditions, aligning with EU priorities in digital health and sustainable innovation. The project's scale is significant, potentially reducing healthcare costs by enabling remote monitoring and early intervention.
Activities: Over the two-year duration, the project focused on the design, fabrication, and validation of flexible PHE sensors. Key activities included sputtering deposition of bi-layer (e.g. NiFe/IrMn) and tri-layer (e.g. NiFe/Cu/IrMn thin films on polyimide substrates, incorporating elliptical and meander geometries to enhance magnetic anisotropy and signal linearity. An ultralow-noise measurement setup was built from scratch, integrating lock-in amplification and frequency mixing for noise decomposition, achieving sub-nT resolution below 10 Hz in unshielded environments.
Main achievements encompassed the successful fabrication of prototypes that demonstrated over 95% signal retention after 10,000 bending cycles (radii down to 5 mm) and sensitivities up to 500 mV/T. Sensors were validated in forced-MMG experiments on human subjects, tracking skeletal muscle contractions (e.g. forearm) with high spatial resolution. Collaborations led to biodegradable variants using cellulose-based substrates and printable sensors via conductive inks, applied to magnetic particle tracking with <1 mm accuracy. Noise models based on Hooge's parameter were optimized to reduce 1/f noise using capping layers. The project resulted in five peer-reviewed publications, four conference presentations (such as INTERMAG 2024, JEMS 2025), and leadership in IEEE standardization (P3599 working group chair). Technology transfer discussions with industry partners (Foerster, Bosch) explored scalability for non-destructive testing (NDT).
Achievements:
The project combined thin-film device engineering, low-noise electronics, mechanical characterisation, and application-level validation:
a) Device engineering — Reproducible fabrication flows for flexible bi-layer and tri-layer PHE sensors on polymer substrates were established. Two complementary geometries (elliptical for high linearity and meander for enhanced sensitivity) were developed and optimised, with stack-level interventions (spacer/capping layers and exchange bias, where applicable) to stabilise magnetisation under flex.
b) Low-noise instrumentation — A customized ultralow-noise measurement platform and data pipeline were designed and constructed to quantify device transfer curves and noise spectra down to the sub-nT regime (notably below 10 Hz). Frequency-mixing and readout optimisation reduced effective 1/f contributions, enabling robust comparison between flexible prototypes and rigid references.
c)Mechanical and magnetic characterisation — Systematic bending and cyclic-flex tests were performed to map sensitivity, offset drift, and 1/f noise as functions of curvature and cycle number. The best prototypes showed improved sensitivity, enhanced linearity across the operational range, and mechanical resilience suitable for wearable applications.
d)Application validation — Flexible sensors were integrated into a pilot forced-MMG measurement chain and captured biomagnetic signatures above the laboratory noise floor; analysis and manuscript preparation are ongoing. Devices were also trialled in magnetic-particle tracking experiments, demonstrating multi-use applicability.
e)Dissemination & translation — The project led to multiple conference presentations, invited talks, and active industrial discussions to evaluate technology transfer. Standardisation momentum was initiated through leadership roles in planar-Hall sensor characterisation working groups (standard development ongoing).
Collectively, these activities delivered prototype sensors, a validated low-noise testbed, and initial application evidence in MMG and particle tracking.
Main achievements encompassed the successful fabrication of prototypes that demonstrated over 95% signal retention after 10,000 bending cycles (radii down to 5 mm) and sensitivities up to 500 mV/T. Sensors were validated in forced-MMG experiments on human subjects, tracking skeletal muscle contractions (e.g. forearm) with high spatial resolution. Collaborations led to biodegradable variants using cellulose-based substrates and printable sensors via conductive inks, applied to magnetic particle tracking with <1 mm accuracy. Noise models based on Hooge's parameter were optimized to reduce 1/f noise using capping layers. The project resulted in five peer-reviewed publications, four conference presentations (such as INTERMAG 2024, JEMS 2025), and leadership in IEEE standardization (P3599 working group chair). Technology transfer discussions with industry partners (Foerster, Bosch) explored scalability for non-destructive testing (NDT).
Achievements:
The project combined thin-film device engineering, low-noise electronics, mechanical characterisation, and application-level validation:
a) Device engineering — Reproducible fabrication flows for flexible bi-layer and tri-layer PHE sensors on polymer substrates were established. Two complementary geometries (elliptical for high linearity and meander for enhanced sensitivity) were developed and optimised, with stack-level interventions (spacer/capping layers and exchange bias, where applicable) to stabilise magnetisation under flex.
b) Low-noise instrumentation — A customized ultralow-noise measurement platform and data pipeline were designed and constructed to quantify device transfer curves and noise spectra down to the sub-nT regime (notably below 10 Hz). Frequency-mixing and readout optimisation reduced effective 1/f contributions, enabling robust comparison between flexible prototypes and rigid references.
c)Mechanical and magnetic characterisation — Systematic bending and cyclic-flex tests were performed to map sensitivity, offset drift, and 1/f noise as functions of curvature and cycle number. The best prototypes showed improved sensitivity, enhanced linearity across the operational range, and mechanical resilience suitable for wearable applications.
d)Application validation — Flexible sensors were integrated into a pilot forced-MMG measurement chain and captured biomagnetic signatures above the laboratory noise floor; analysis and manuscript preparation are ongoing. Devices were also trialled in magnetic-particle tracking experiments, demonstrating multi-use applicability.
e)Dissemination & translation — The project led to multiple conference presentations, invited talks, and active industrial discussions to evaluate technology transfer. Standardisation momentum was initiated through leadership roles in planar-Hall sensor characterisation working groups (standard development ongoing).
Collectively, these activities delivered prototype sensors, a validated low-noise testbed, and initial application evidence in MMG and particle tracking.
Flexi-MMG advanced beyond current PHE sensor technologies by achieving a 4-fold improvement in signal-to-noise ratio and twofold sensitivity enhancement through innovative meander designs and material optimizations, surpassing rigid counterparts limited to shielded environments. Unlike traditional SQUID-based MMG systems, which require cryogenic cooling and are bulky, these flexible sensors operate at room temperature, enabling portable, skin-conformable devices for real-world applications.
Potential impacts include revolutionizing neuromuscular diagnostics with non-invasive, high-resolution muscle mapping, supporting IoT-integrated wearables for rehabilitation, and promoting sustainable sensing via biodegradable materials that reduce electronic waste. Key needs for uptake involve further demonstration, IPR protection for meander geometries , and standardization efforts through IEEE. Commercialization could be accelerated via access to markets like automotive sensing and soft robotics, with regulatory frameworks (EU Medical Device Regulation) ensuring safety. Overall, the results provide a foundation for next-generation biomagnetic tools, with manuscripts on forced-MMG and particle tracking highlighting translational potential.
In summary, key advances produced by the project exceed the current state of the art in three areas:
a) Flexible PHE devices with operational sub-nT sensitivity in realistic (non-shielded) setups. Achieving such sensitivity in mechanically flexible magnetoresistive elements is novel and removes a major barrier for portable biomagnetic sensing.
b) Mechanical robustness with preserved linearity. Stack engineering and geometry optimisation produced sensors whose sensitivity and linear operating range are maintained under bending and cyclic stress — a decisive improvement for wearable deployment.
c) System-level integration for MMG. Demonstrating forced-MMG capture with flexible PHE sensors provides proof-of-concept that compact, low-cost magnetometers can be used for muscle biomagnetism; this opens pathways for ambulatory diagnostics and soft-robotics sensing.
To enable uptake and commercialisation, the following technical and non-technical needs have been identified: extended validation in physiological/clinical settings; packaging and long-term reliability studies; integration with low-power readout electronics and wireless telemetry; intellectual-property and regulatory strategy; and pilot manufacturing routes (including printable and biodegradable sensor variants). The project has already initiated steps toward several of these (industrial dialogues, standardisation activity, and collaborative proposals).
Potential impacts include revolutionizing neuromuscular diagnostics with non-invasive, high-resolution muscle mapping, supporting IoT-integrated wearables for rehabilitation, and promoting sustainable sensing via biodegradable materials that reduce electronic waste. Key needs for uptake involve further demonstration, IPR protection for meander geometries , and standardization efforts through IEEE. Commercialization could be accelerated via access to markets like automotive sensing and soft robotics, with regulatory frameworks (EU Medical Device Regulation) ensuring safety. Overall, the results provide a foundation for next-generation biomagnetic tools, with manuscripts on forced-MMG and particle tracking highlighting translational potential.
In summary, key advances produced by the project exceed the current state of the art in three areas:
a) Flexible PHE devices with operational sub-nT sensitivity in realistic (non-shielded) setups. Achieving such sensitivity in mechanically flexible magnetoresistive elements is novel and removes a major barrier for portable biomagnetic sensing.
b) Mechanical robustness with preserved linearity. Stack engineering and geometry optimisation produced sensors whose sensitivity and linear operating range are maintained under bending and cyclic stress — a decisive improvement for wearable deployment.
c) System-level integration for MMG. Demonstrating forced-MMG capture with flexible PHE sensors provides proof-of-concept that compact, low-cost magnetometers can be used for muscle biomagnetism; this opens pathways for ambulatory diagnostics and soft-robotics sensing.
To enable uptake and commercialisation, the following technical and non-technical needs have been identified: extended validation in physiological/clinical settings; packaging and long-term reliability studies; integration with low-power readout electronics and wireless telemetry; intellectual-property and regulatory strategy; and pilot manufacturing routes (including printable and biodegradable sensor variants). The project has already initiated steps toward several of these (industrial dialogues, standardisation activity, and collaborative proposals).