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.
