Korea Institute of Machinery & Materials · A Korean research team has developed an ultra-compact 3-axis magnetic sensor that can be applied to robotic fingertips and medical devices that require highly precise motion
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A Korean research team has developed an ultra-compact 3-axis magnetic sensor that can be applied to surgical robots requiring highly precise movements.
A Korean research team has developed an ultra-compact 3-axis magnetic sensor that can be applied to robotic fingertips and medical devices that require highly precise motion.
The Korea Institute of Machinery & Materials (KIMM) announced on the 6th that a research team led by Principal Researcher Oh Sun-jong at the AI Robot Research Center’s Bio-Robotics Lab has developed a sensor capable of simultaneously measuring magnetic fields in the x, y, and z directions. The research results were published on June 13 in the international journal Advanced Functional Materials.
Typically, robots use magnets to sense their motion in three-dimensional space. A magnet attached to moving parts, such as robot fingers or joints, changes the surrounding magnetic field as it moves, and this variation is measured by a magnetic field sensor.
To detect changes in the magnetic field in three-dimensional space, it is necessary to measure magnetic fields in the x, y, and z directions. Conventional planar sensors can only measure magnetic fields in the x and y directions (left–right and front–back), and it is difficult to measure magnetic fields in the z direction, which is perpendicular to the sensor surface. To measure the magnetic field in the z direction, an additional sensor perpendicular to the x–y plane must be installed.
The research team solved this problem by forming a “flux guide” on top of the sensor to redirect the direction of the magnetic field. The flux guide, made of superparamagnetic nanoparticles whose magnetization disappears when the external magnetic field is removed, guides vertically incident magnetic fields into the planar direction that the sensor can detect, enabling a single sensor to measure magnetic fields in all three directions.
“The key distinction of this research is that we can measure magnetic fields in all three directions—x, y, and z—using a planar sensor alone, without separately installing a vertical sensor,” said Principal Researcher Oh. “Because the sensor uses only a single planar device, it is very thin, which makes it well suited for use in wearable devices.”
The z-axis magnetic-field sensitivity of the ultra-compact 3-axis magnetic sensor developed by the team is about three times higher than that of existing sensors, and the magnetic-field conversion efficiency, which converts vertical magnetic fields into a direction measurable by the sensor, has been improved by up to 40%.
The sensor measures 500 micrometers (μm; 1 μm is one-millionth of a meter) by 500 μm, and even when four sensing elements operate simultaneously, its power consumption is only about 16 milliwatts (mW; 1 mW is one-thousandth of a watt).
Conventional flux guides use ferromagnetic materials such as nickel or permalloy. Ferromagnetic materials exhibit “magnetic hysteresis,” in which magnetization remains even after the magnetic field is removed, requiring an additional reset circuit. Their fabrication process is also complex, involving electroplating or precision machining.
The research team applied superparamagnetic nanoparticles, whose magnetization disappears when the external magnetic field is removed, enabling repeated magnetic-field measurements without a separate reset circuit. They also simplified the fabrication process by turning the nanoparticles into an ink and printing them directly onto the sensor.
The developed sensor can also be extended into a tactile sensor capable of precisely detecting forces generated when a robot comes into contact with an object, in addition to measuring magnetic fields. Postdoctoral researcher Jeon Chang-yeob, who took part in the study, said, “We plan to broaden the application scope to areas that require precise measurement of motion and force, such as robotic hands, soft robots, human–machine interfaces, and medical devices.”
Source
- dongascience.com (2026-10-06)
- Original article: Korea Institute of Machinery & Materials develops ultra-compact 3-axis magnetic sensor for robotic fingertips
- DongA Science
- https://dongascience.com/en/news/80199