Migrating birds might be able to see the earth’s magnetic field

Scientists have proven that migrating birds like the European robin can perceive the earth's magnetic field, but the biology and physics beneath such talents remain mysterious. That's because, while many animal senses rely on the enhanced collection of sound or light through classical physics, birds appear to rely on quantum mechanics.

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‘Imagine that you have ultra-light and highly stretchable electronics. If you attach it to your skin, you will not even sense it.’

Understanding how it’s done could help researchers to devise ways to use magnetism to improve electronics, and even give humans their own magnetic navigation tools.

Professor Peter Hore, from the University of Oxford, UK, is leading a team looking to break down how quantum reactions in birds' eyes can register small changes in magnetic field strengths as part of the CHEMNAV project, funded by the European Research Council (ERC).

‘One of the things we're moving toward are conditions in the laboratory that resemble more closely those in the cell,’ Prof. Hore explained. 

Scientists believe the earth's magnetic field changes the spin of particles inside the bird's eye.

Prof. Hore's team is using model reactions and computer simulations to figure out which particles give the most sensitive response to magnetism.

He is confident that the results of such research could inspire better semiconductor electronics that use magnetic sensing, or they could even be used to replicate bird navigation.

‘There is scope for using the ideas that come of these kinds of studies to create devices which may be useful for humans,’ he said.

Flexible, stretchable

Magnetic sensors like the ones used by birds have inspired other EU scientists to do just that. Dr Denys Makarov is working to supplant the rigid circuits we're familiar with in electronics with shapeable magnetic sensors as part of the SMaRT project, also funded by the ERC.

At the Leibniz Institute for Solid State and Materials Research in Dresden, Germany, his team is working to create flexible, stretchable magnetic sensors that can be used to detect motion or proximity.

‘You can put it on a sphere, on a knee ... and you can stretch three times the initial length of the magnetic sensor without changing any performance,' he said.

In collaboration with the groups from Chemnitz University of Technology in Germany, and the universities of Tokyo and Osaka in Japan, Dr Makarov and his team successfully used these new sensors to make devices that can be placed on a person's skin to allow them to interact with machines touchlessly.

‘Imagine that you have ultra-light and highly stretchable electronics. If you attach it to your skin, you will not even sense it,’ he said.

They used the technology to make a motion and displacement sensors to make a second 'electronic' skin which could be used to replicate the navigational skills of birds by detecting the earth's magnetic field.

These magnetic sensors could be used, for example, to monitor the displacements of joints and the expansion and contraction of muscles. That could enable doctors to monitor someone's heart in real time and pick up any irregularities before they develop into a heart attack.

‘Everything which is moving, everything which is displacing can be detected using magnetic field sensors,’ Dr Makarov said.