Whether it's the non-contact measurement of heart activity and brainwaves or detecting ore deposits and archaeological remains buried deep underground, the solution that physicists from Saarland University are bringing to Hannover should help. The scientists have developed magnetic field sensors that are breaking sensitivity records and opening up a whole range of potential new applications. Professor Uwe Hartmann and his research team have developed a system that allows them to detect weak magnetic signals over large distances in normal environments - that is, without needing a vacuum, low temperatures or shielding. Even when there are numerous sources of interference, their system can detect signal strengths far below a billionth of a tesla - about a million times smaller than the Earth’s magnetic field. This means it can be used to detect biomagnetic signals in the human body and geophysical phenomena alike.
The research team is at HANNOVER MESSE 2019 in search of partners who can help develop the new measuring methods further. Experimental physicist Professor Hartmann has a nifty example to illustrate how impressive the team's achievement is: "You could say the precision of our technique is like being able to locate a grain of sand in a mountain range. We can detect over relatively large distances magnetic fields that are approximately a million times weaker than the Earth's magnetic field - just a few picotesla, that is a millionth of a millionth of a tesla." To date, sensors working under normal ambient conditions have been able to detect magnetic fields that are about a thousand times smaller than the Earth's magnetic field.
Hartmann and his team have been involved in several projects that have focused on filtering out interference signals from measurement data. For instance, the researchers developed a smart sensor cable in which the magnetometers are connected to one another in a network. A number of these systems are currently being trialed as components in airport traffic management systems, for instance. Although the highly sensitive magnetic field sensors on show in Hannover are still, in essence, basic research, there are a wide range of potential applications. They could, for example, be used for diagnostic purposes in cardiology or neurology, where they could complement existing techniques such as ECG (electrocardiography) or EEG (electroencephalography). Another potential use is in geophysical sensing when searching for crude oil, mineral deposits or archaeological remains.