US researchers have demonstrated a new magnetic sensor (“the size of a grain of rice”) that can detect miniscule magnetic field fluctuations. According to the U.S. Department of State’s propaganda release, this new chip-scale magnetic sensor could have a potential use in future medical devices.
And this is how it works:
The sensor works by detecting minute changes in the energy levels of electrons in the presence of a magnetic field. A tiny sample of the element rubidium is heated within a sealed, transparent cell to form a rubidium vapor. Light from a semiconductor laser is transmitted through the atomic vapor. In the presence of a magnetic field, the amount of laser light that is absorbed by the atoms changes and this is detected by a photocell. Larger magnetic fields produce proportionally bigger changes in the atomic energy levels and change the absorption by the atom.
The key advantages of the new sensor, says Peter Schwindt, one of the NIST developers, are its accuracy and sensitivity given its small size.
The original press release…