Windmill-shaped device enhances magnetic sensor performance
Windmill-shaped device enhances magnetic sensor performance lead image
Small on-chip devices are becoming more commonplace as the technology grows smaller and more advanced. These devices often include magnetic sensors, which have uses in robotics, medicine, telecommunications, manufacturing, consumer electronics, and many other applications. These magnetic sensors must be planar to fit on the chip while remaining highly sensitive to even weak magnetic fields.
Bort-Soldevila et al. developed a windmill-shaped system using a ferromagnetic metamaterial to concentrate magnetic fields to a central sensor. In proof-of-concept experiments, the concentrated field from the device reached levels over 100 times stronger than the applied field.
The windmill design of the concentrator funnels magnetic field lines inward to the center by providing a favorable path through the material.
“The windmill geometry is used because it approximately mimics the ideal concentrator,” said author Carles Navau. “In the ideal case, the radial permeability should be infinite while the angular one should be zero. In our case, the blades give the radial permeability, and a reduced angular permeability is provided by the gaps of the windmill.”
The authors demonstrated the performance of their device using theoretical calculations and a proof-of-concept experimental test. In future work, they plan to shrink the size of their concentrator for on-chip integration, and study related effects like demagnetizing fields and magnetic domains.
“Furthermore, the central region has to be filled by a ferromagnetic material with a slit that could be filled by the sensor,” said Navau. “The geometry of the slit will probably be critical for the performance of the device.”
Source: “Enhanced magnetic field concentration using windmill-like ferromagnets,” by Natanael Bort-Soldevila, Jaume Cunill-Subiranas, Aleix Barrera, Nuria Del-Valle, Alejandro V. Silhanek, Vojtěch Uhlíř, Simon Bending, Anna Palau, and Carles Navau, APL Materials (2024). The article can be accessed at https://doi.org/10.1063/5.0187035 .
