Boulder, Colo. – A tiny sensor that can detect magnetic field changes as small as 70 femtoteslas—equivalent to the brain waves of a person daydreaming—has been demonstrated at the National Institute of Standards and Technology (NIST). The sensor could be battery-operated and could reduce the costs of non-invasive biomagnetic measurements such as fetal heart monitoring. The device also may have applications such as homeland security screening for explosives.
