Korea's KIMM Develops World-First Ultra-Small 3-Axis Magnetic Sensor

Recap

Source: 로봇신문, report of Oct. 6, 2026

According to the report, researchers at the Korea Institute of Machinery and Materials (KIMM) have developed what they describe as the world's first ultra-small 3-axis magnetic sensor. The device measures magnetic fields in the x, y, and z directions simultaneously without requiring a separate reset circuit. This is achieved by printing superparamagnetic nanoparticles as a flux guide onto a planar Hall magnetoresistance (PHMR) device. The team reports that this approach eliminates the magnetic hysteresis issues associated with traditional ferromagnetic materials like nickel or permalloy, which typically require complex electroplating and reset electronics.

The sensor measures 500 μm × 500 μm and consumes only 16 mW when all four sensing elements are active. By applying an external magnetic field during the curing process to align the nanoparticles vertically, the team increased the z-axis sensitivity by approximately 3 times and improved the magnetic field conversion efficiency to a maximum of 40%. The research team, led by Senior Researcher Oh Sun-jong, also demonstrated that the platform can be extended into a multi-axis tactile sensor by combining it with an elastic body containing a permanent magnet, allowing it to measure both pushing and pulling forces.

The study was conducted in collaboration with a research team led by Professor Kim Cheol-gi at DGIST. The results were published in the journal Advanced Functional Materials in June 2026 and selected as a front cover paper. The work was supported by the Ministry of Science and ICT, the National Research Foundation of Korea, and the Ministry of Trade, Industry and Energy.

Context

Magnetic sensors are critical for robot joint encoders and tactile feedback, but traditional 3-axis sensors often struggle with the vertical (z-axis) component due to the planar nature of the sensing elements. Conventional solutions use ferromagnetic flux guides, which suffer from magnetic hysteresis—meaning they retain magnetization after the external field is removed. This requires additional reset circuits and complex manufacturing processes like electroplating, making them difficult to miniaturize for use in tight spaces like robot fingers.

The use of superparamagnetic nanoparticles is a significant shift because these materials lose their magnetization once the external field is removed, naturally solving the hysteresis problem. Furthermore, the inkjet printing method allows for a much simpler fabrication process compared to traditional microfabrication, which is a major advantage for scaling up production of small, low-power sensors.

Robot's take

This development is highly relevant for the next generation of dexterous robot hands and soft robots, where space and power consumption are at a premium. The ability to integrate a 3-axis magnetic sensor with tactile force sensing on a single 500-micron platform could significantly reduce the complexity of sensor arrays in robotic fingertips. However, it is not yet clear how well this sensor performs in high-temperature or high-vibration industrial environments, which are common in real-world robotic applications. The next step will likely be to see if this technology can be integrated into commercial robotic joints and tactile skins, moving from lab demonstrations to practical, durable components.