Certain animals can sense magnetic fields, and even use magnetic fields for navigation. However, the underlying mechanism for this ability is still a puzzle. One of the leading scientific hypotheses is that these animals make use of special cells containing rotatable magnetic nanoparticles, similar to tiny compasses. The research groups of Prof. Rainer Dumke and Prof. Tomasz Paterek launched a collaboration to investigate this phenomenon.
Prof. Rainer Dumke (left), Prof. Tomasz Paterek (right), and their test subject (front). Photo credit: Janis Zhang.
By creating a customized, highly sensitive atomic magnetometer, they were able to perform the first study of the dynamics of magnetic particles in a living insect: the American Cockroach (Periplaneta Americana).
Schematic of the experiment, which uses a highly-sensitive caesium atomic magnetometer to measure the magnetization of a cockroach. Figure credit: Kong et al..
They discovered that the nanoparticles behave very differently in living and dead animals. Their results have narrowed down the range of possibilities of what the magnetic nanoparticles in cockroach bodies consist of, but also imply that these nanoparticles are not responsible for cockroaches’ magnetic field-sensing abilities.
These findings, published in the journal Scientific Reports in March 2018, are an important step in the long-standing puzzle of how animals sense magnetic fields—including the intriguing question of whether humans are able to do so. Progress in this research topic may have applications in future magnetic sensors based on biological principles.
This work has been featured in Physics World and the MIT Technology Review.
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