The device detects vanishingly weak magnetic signals, such as those produced by the human brain, and can operate at room temperature
3-MIN READ3-MINZhang Tongin BeijingPublished: 8:00pm, 5 Sep 2026Chinese researchers have developed a table-top magnetic sensor that operates at room temperature and can spot magnetic signals a billion times fainter than the Earth’s own field.The Levitated Magnet Magnetometer (LeMaMa) functions like a compass with a needle that floats in mid-air with virtually no friction. By tracking the needle’s tiny deflections, the team can measure magnetic fields down to the femtotesla level – an advance that could widen the hunt for elusive dark matter particles or monitor brain signals.“The combination of room-temperature operation, tiny components and high sensitivity makes LeMaMa promising for fundamental physics experiments,” Ji Wei, assistant professor at Peking University’s school of physics and corresponding author of the study, told Guangming Daily on August 17.
Until now, femtotesla-level measurements have mainly relied on two approaches. One is the superconducting quantum interference device (Squid) magnetometer, which offers excellent sensitivity but must operate at cryogenic temperatures near absolute zero, requiring bulky and expensive liquid-helium cooling.
