Magnetoelastic films resonate at a characteristic frequency that is dependent on their environment.
This frequency can be measured remotely by magnetic pick-up coils making physical connections unnecessary. This method of remote sensing allows for testing of chemical parameters inside sealed containers or difficult to reach environments. The use of magnetoelastic films as sensing element is analogous to mass sensitive techniques such as surface plasmon resonance and quartz crystal microbalance. Enzyme sensors based on a magnetoelastic Fe 41 Ni 41 Mo 5 B 7 alloy are being developed. The alloy is first silanized to introduce amine groups on its surface, which are subsequently used to immobilize enzymes.