China develops microscopic magnetic sensor for submarine detection

Researchers from the Hefei Institutes of Physical Science and the Ningbo Institute of Materials Technology and Engineering, both branches of the Chinese Academy of Sciences, have developed a microscopic magnetic sensor capable of detecting the faint magnetic signatures of steel-hulled submarines.

The sensor is extremely compact, measuring approximately 20 by 20 microns, which allows for potential integration into small consumer electronics such as smartwatches. By utilizing the Hall effect and leveraging “spin-texture dynamics,” the team created a low-noise device that can distinguish weak magnetic signals from internal fluctuations.

While traditional sonar relies on acoustic waves, this technology focuses on magnetic fields. The researchers stated the sensor possesses a sensitivity that could theoretically detect a submerged submarine from a distance of up to 500 metres (approximately 1,640 feet). Beyond maritime applications, the technology may also have uses in biomedical devices.