Periodic Reporting for period 1 - NANOSENSE (Nanoscale Integrated Magnetic Field Sensor)
Berichtszeitraum: 2023-01-01 bis 2024-06-30
Magnetic sensors are present everywhere in our daily lives. We often use them in cars, robotics, medical applications, for power sensing, electronic compass, etc. Among them, magnetoresistive sensors play an increasing role thanks to their relatively small size, good sensitivity and low cost. However, magnetoresistive sensors saturate above typically a few milli-Tesla which is too low for a number of applications. Besides, reducing the sensor footprint is important in terms of costs. In addition, smaller sensors have also a reduced power consumption which is very important for wearable applications and sensors used in Internet of Things. Therefore, it is commercially desirable to be able to develop a low cost, nano-size, magnetoresistive sensor in which the dynamic range could be extended and easily adjusted in the range 80mT-400mT commonly used in linear or angular encoders.
Within an ERC project which just ended entitled “CMOS/Magnetoelectronic Integrated Circuits with Multifunctional Capabilities”, a novel concept of vortex magnetic field nanosensor sensitive to out-of-plane field was proposed and patented. Initial experiments performed within this ERC project provided very promising results. The purpose of this ERC PoC project is to make a full proof of concept of this sensor demonstrating its outstanding performance and subsequently move towards a start-up creation of licensing of the technology to an existing sensors manufacturer. Within NANOSENSE, we aim to achieve gains over existing sensors by 10x in terms of footprint reduction, 50x in power consumption, 10x in signal to noise ratio while increasing the sensing range up to ~800mT. This will make these sensors suitable for integration in sensors network for IoT, sensors for wearable applications, automotive, detection of leakage current in electronic circuits, detection of microcracks in metals, navigation of surgical tools (e.g.endoscopes).
Within an ERC project which just ended entitled “CMOS/Magnetoelectronic Integrated Circuits with Multifunctional Capabilities”, a novel concept of vortex magnetic field nanosensor sensitive to out-of-plane field was proposed and patented. Initial experiments performed within this ERC project provided very promising results. The purpose of this ERC PoC project is to make a full proof of concept of this sensor demonstrating its outstanding performance and subsequently move towards a start-up creation of licensing of the technology to an existing sensors manufacturer. Within NANOSENSE, we aim to achieve gains over existing sensors by 10x in terms of footprint reduction, 50x in power consumption, 10x in signal to noise ratio while increasing the sensing range up to ~800mT. This will make these sensors suitable for integration in sensors network for IoT, sensors for wearable applications, automotive, detection of leakage current in electronic circuits, detection of microcracks in metals, navigation of surgical tools (e.g.endoscopes).
The main achievements of our NANOSENSE ERC PoC project can be summarized as follows:
1. Improved Sensor Design: The PSA-vortex sensor was designed with a unique aspect ratio (thickness/diameter near 1), which significantly increased the vortex core size (up to 20nm) compared to conventional vortex sensors sensitive to in-plane fields. This led to the ability to detect out-of-plane magnetic fields with high precision.
2. Enhanced Dynamic Range: The PSA-vortex sensors were shown to exhibit a dynamic range exceeding 200mT, which is much broader than that of conventional in-plane vortex sensors (40-80mT). This makes it well-suited for applications requiring high dynamic range, such as automotive positioning sensors.
3. Stability Improvements: By adjusting the composition of the pinned layer, the PSA-vortex sensor was stabilized to prevent random switching between two possible branches of the transfer curve, improving its reliability and dynamic range.
4. Noise Reduction: The PSA-vortex sensor showed reduced noise levels, particularly from defects and disorder, resulting in a 28dB improvement in signal-to-noise ratio (SNR) compared to conventional vortex sensors. Further gain in SNR will be obtained by addressing local defects in the material through further material optimization.
5. Tunability: The sensor's dynamic range and sensitivity could be finely tuned by adjusting the aspect ratio and material composition. This tunability makes the sensor highly versatile for a range of applications as well as for realizing memory (STT-MRAM) and sensor function with the same stack by adjusting only the diameter of the device.
6. Sensitivity and Future Optimization: The current sensitivity of the PSA-vortex sensor ranged from 0.02%/mT to 0.20%/mT, lower than conventional sensors but consistent with the trade-off for higher dynamic range. However, there is potential for improvement by increasing the resistance-area (RA) product, which could lead to a sensitivity as high as 1%/mT in future iterations.
These developments represent significant progress in improving vortex-based sensor technology, particularly for applications requiring high dynamic range, stability, and noise reduction.
1. Improved Sensor Design: The PSA-vortex sensor was designed with a unique aspect ratio (thickness/diameter near 1), which significantly increased the vortex core size (up to 20nm) compared to conventional vortex sensors sensitive to in-plane fields. This led to the ability to detect out-of-plane magnetic fields with high precision.
2. Enhanced Dynamic Range: The PSA-vortex sensors were shown to exhibit a dynamic range exceeding 200mT, which is much broader than that of conventional in-plane vortex sensors (40-80mT). This makes it well-suited for applications requiring high dynamic range, such as automotive positioning sensors.
3. Stability Improvements: By adjusting the composition of the pinned layer, the PSA-vortex sensor was stabilized to prevent random switching between two possible branches of the transfer curve, improving its reliability and dynamic range.
4. Noise Reduction: The PSA-vortex sensor showed reduced noise levels, particularly from defects and disorder, resulting in a 28dB improvement in signal-to-noise ratio (SNR) compared to conventional vortex sensors. Further gain in SNR will be obtained by addressing local defects in the material through further material optimization.
5. Tunability: The sensor's dynamic range and sensitivity could be finely tuned by adjusting the aspect ratio and material composition. This tunability makes the sensor highly versatile for a range of applications as well as for realizing memory (STT-MRAM) and sensor function with the same stack by adjusting only the diameter of the device.
6. Sensitivity and Future Optimization: The current sensitivity of the PSA-vortex sensor ranged from 0.02%/mT to 0.20%/mT, lower than conventional sensors but consistent with the trade-off for higher dynamic range. However, there is potential for improvement by increasing the resistance-area (RA) product, which could lead to a sensitivity as high as 1%/mT in future iterations.
These developments represent significant progress in improving vortex-based sensor technology, particularly for applications requiring high dynamic range, stability, and noise reduction.
The project has made significant progress in developing PSA-vortex sensors, but to ensure further uptake and success, several areas need more work:
1. Research and Development Needs:
o Further research is required to reduce noise by addressing interface imperfections and improving material quality.
o Experimental implementation of techniques like the Wheatstone bridge for enhancing sensitivity and mitigating noise should be prioritized. This configuration offers potential for high-performance amplification and noise reduction.
o Temperature dependence of sensitivity must be studied more accurately using advanced methods such as lock-in modulation. It should then be minimized by adjusting stack composition so as to balance the thermal variation of tunnel magnetoresistance with the thermal variation of vortex annihilation field.
2. Demonstration and Testing:
o Prototype validation through co-fabrication of sensor and memory cells has shown potential for both sensor and memory applications. However, further demonstration is needed to optimize the trade-off between memory retention and sensor sensitivity.
o Temperature-sensitive behavior must be better understood through more refined testing methodologies. Addressing the lack of clear trends in current sensitivity measurements will be crucial for applications in industries like automotive, where temperature stability is vital.
3. Market and Commercialization Opportunities:
o Automotive industry remains a key market, particularly for magnetic field sensors in encoders for various car systems. Further development must ensure that these sensors meet the reliability and temperature stability requirements for automotive applications.
o Miniaturization of the sensors, already shown to be competitive with Hall sensors in size, should be leveraged. Further demonstrations could make the PSA-vortex sensors commercially viable in applications that demand both compactness and high resolution.
o Collaborations with industrial players must continue to solidify pathways to commercialization. The project’s patent portfolio, including an upcoming second patent, positions it well for exploitation.
4. Supportive Frameworks:
o Access to markets and finance could be enhanced through partnerships with companies interested in licensing the technology, particularly in the automotive sector.
5. Future IP and Exploitation Strategies:
o The project has already filed a patent for the PSA-vortex sensor and is preparing a second. This intellectual property (IP) strategy is crucial for maintaining a competitive edge in the market.
o Commercialization plans include licensing the technology to companies. One has already been identified. Building on existing relationships with industry leaders is key to moving from research to product deployment.
In summary, the project is well-positioned for success, but continued efforts in research, demonstration, and strategic partnerships will be essential to achieve commercialization and further uptake.
1. Research and Development Needs:
o Further research is required to reduce noise by addressing interface imperfections and improving material quality.
o Experimental implementation of techniques like the Wheatstone bridge for enhancing sensitivity and mitigating noise should be prioritized. This configuration offers potential for high-performance amplification and noise reduction.
o Temperature dependence of sensitivity must be studied more accurately using advanced methods such as lock-in modulation. It should then be minimized by adjusting stack composition so as to balance the thermal variation of tunnel magnetoresistance with the thermal variation of vortex annihilation field.
2. Demonstration and Testing:
o Prototype validation through co-fabrication of sensor and memory cells has shown potential for both sensor and memory applications. However, further demonstration is needed to optimize the trade-off between memory retention and sensor sensitivity.
o Temperature-sensitive behavior must be better understood through more refined testing methodologies. Addressing the lack of clear trends in current sensitivity measurements will be crucial for applications in industries like automotive, where temperature stability is vital.
3. Market and Commercialization Opportunities:
o Automotive industry remains a key market, particularly for magnetic field sensors in encoders for various car systems. Further development must ensure that these sensors meet the reliability and temperature stability requirements for automotive applications.
o Miniaturization of the sensors, already shown to be competitive with Hall sensors in size, should be leveraged. Further demonstrations could make the PSA-vortex sensors commercially viable in applications that demand both compactness and high resolution.
o Collaborations with industrial players must continue to solidify pathways to commercialization. The project’s patent portfolio, including an upcoming second patent, positions it well for exploitation.
4. Supportive Frameworks:
o Access to markets and finance could be enhanced through partnerships with companies interested in licensing the technology, particularly in the automotive sector.
5. Future IP and Exploitation Strategies:
o The project has already filed a patent for the PSA-vortex sensor and is preparing a second. This intellectual property (IP) strategy is crucial for maintaining a competitive edge in the market.
o Commercialization plans include licensing the technology to companies. One has already been identified. Building on existing relationships with industry leaders is key to moving from research to product deployment.
In summary, the project is well-positioned for success, but continued efforts in research, demonstration, and strategic partnerships will be essential to achieve commercialization and further uptake.