image: State-of-the-art and 3-axis pyramid device. a Our novel pyramid Hall device. b A standard 3-axis Hall sensor, composed of one planar Hall device and two vertical Hall devices. c The flat 8-contact Hall device, proposed by Schott9. d Sander’s hexagonal prism Hall device11. e An IMC Hall device12. f SEM image of the pyramid device, with a tilting angle of 30°. g SEM image of the pyramid device, with no tilting angle. h Optical microscope image of the sensor. The pyramid size and the contact dimensions are highlighted in the picture.
Credit: Microsystems & Nanoengineering
A team of researchers has developed a pioneering 3-axis Hall-effect magnetic sensor based on an inverted pyramid structure. This innovative design offers significant advancements in both sensitivity and offset reduction, positioning it as a promising solution for applications requiring precise and reliable magnetic field detection in automotive, industrial, and consumer electronics.
Magnetic sensors, especially Hall-effect sensors, are essential in a broad range of industries, from automotive and industrial systems to consumer electronics and medical devices. Despite their reliability and low cost, existing 3-axis Hall sensors face significant challenges, including limited sensitivity, large footprints, and high offsets. These limitations hinder their ability to meet the growing demands for miniaturization and precision in modern electronics. As devices continue to shrink and require more accurate magnetic sensing, the need for advanced solutions has never been greater.
In a new study (DOI: 10.1038/s41378-025-00876-9) published in Microsystems & Nanoengineering on February 14, 2025, researchers from Department of Microelectronics, Delft University of Technology unveiled a novel 3-axis Hall-effect magnetic sensor with an inverted pyramid structure. Using a combination of micro-electromechanical systems (MEMS) micromachining and complementary metal-oxide semiconductor (CMOS) processing, the device can detect both in-plane and out-of-plane magnetic fields within a single compact structure. This sensor outperforms traditional Hall sensors by employing an innovative current-spinning method that reduces offset by one to three orders of magnitude, addressing a major challenge in magnetic field sensing.
The new sensor showcases exceptional performance, with high current-related sensitivity ranging from 64.1 to 198 V A−1 T−1 and voltage-related sensitivity between 14.8 and 21.4 mV V−1 T−1. It also boasts a low crosstalk rate of less than 4.7%, ensuring accurate readings. With a thermal noise floor of approximately 0.5 μT/√Hz, this sensor is ideal for high-precision applications. Notably, the sensor’s compact design integrates multiple sensing modes into a single structure, significantly reducing its footprint and improving isotropy compared to existing solutions. While the sensor demonstrates remarkable improvements, the residual offset remains in the millitesla range, signaling potential for further optimization.
Dr. Karen M. Dowling, a leading researcher on the project, emphasized the significance of the breakthrough: "This novel sensor represents a significant step forward in magnetic sensing technology. By integrating an inverted pyramid structure with current-spinning, we have achieved remarkable improvements in sensitivity and offset reduction, paving the way for more precise and reliable magnetic field sensing."
The innovative 3-axis Hall-effect sensor has broad implications across various industries, particularly in areas that require highly precise magnetic field sensing. Its compact design and advanced performance make it an ideal candidate for applications such as position feedback, power monitoring, and robotic motion tracking. As further refinements are made, this technology could revolutionize magnetic sensor integration in everyday devices, driving greater efficiency and reliability across multiple sectors.
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References
DOI
Original Source URL
https://doi.org/10.1038/s41378-025-00876-9
Funding information
This work was funded in part by the European Union.
About Microsystems & Nanoengineering
Microsystems & Nanoengineering is an online-only, open access international journal devoted to publishing original research results and reviews on all aspects of Micro and Nano Electro Mechanical Systems from fundamental to applied research. The journal is published by Springer Nature in partnership with the Aerospace Information Research Institute, Chinese Academy of Sciences, supported by the State Key Laboratory of Transducer Technology.
Journal
Microsystems & Nanoengineering
Subject of Research
Not applicable
Article Title
Inverted pyramid 3-axis silicon Hall-effect magnetic sensor with offset cancellation
Article Publication Date
14-Feb-2025
COI Statement
The authors declare that they have no competing interests.