Skip to main content

Electronic skin points the way north

Electronic skin points the way north :Sensors give humans magnetoception



No bulky gloves, no sophisticated camera systems -- just an ultra-thin golden foil on the middle finger. That's all the Dresden researchers need to control a virtual panda with the help of the Earth's magnetic field. When the hand swipes left, towards the magnetic north, the animal also moves in that direction (a). A swipe to the right, makes it go the opposite way (b). When the hand moves towards the middle, the panda moves back slightly towards the left (c).


While birds are able to naturally perceive the Earth's magnetic field and use it for orientation, humans have so far not come close to replicate this feat -- at least, until now. Researchers at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) in Germany have developed an electronic skin (e-skin) with magnetosensitive capabilities, sensitive enough to detect and digitize body motion in the Earth's magnetic field. As this e-skin is extremely thin and malleable, it can easily be affixed to human skin to create a bionic analog of a compass. This might not only help people with orientation issues, but also facilitate interaction with objects in virtual and augmented reality. The results have been published in the journal Nature Electronics.
Just swipe your hand to the left and the virtual panda on the screen will start making its way towards the bottom left. Swipe your hand to the right and you can make the black-and-white animal face the opposite direction. This demonstration is reminiscent of the famous scene from the movie Minority Report where lead actor Tom Cruise controls a computer with nothing but hand gestures. What was science fiction 16 years ago, has now become reality thanks to Dr. Denys Makarov and his team of HZDR researchers. Neither bulky gloves, cumbersome glasses, nor sophisticated camera systems are required to control the panda's path. All it takes is a sliver of polymer foil, no more than a thousandth of a millimeter thick, attached to a finger -- and the Earth's magnetic field.
"The foil is equipped with magnetic field sensors that can pick up geomagnetic fields," says the lead author Gilbert Santiago Cañón Bermúdez. "We are talking about 40 to 60 microtesla -- that is 1,000 times weaker than a magnetic field of a typical fridge magnet." This is the first demonstration of highly compliant electronic skins capable of controlling virtual objects relying on the interaction with geomagnetic fields. The previous demonstrations still required the use of an external permanent magnet: "Our sensors enable the wearer to continuously ascertain his orientation with respect to the earth's magnetic field. Therefore, if he or the body part hosting the sensor changes orientation, the sensor captures the motion, which is then transferred and digitized to operate in the virtual world."
Just like a regular compass
The sensors, which are ultrathin strips of the magnetic material permalloy, work on the principle of the so-called anisotropic magneto-resistive effect, as Cañón Bermúdez explains: "It means that the electric resistance of these layers changes depending on their orientation in relation to an outer magnetic field. In order to align them specifically with the Earth's magnetic field, we decorated these ferromagnetic strips with slabs of conductive material, in this case gold, arranged at a 45-degree angle. Thus, the electric current can only flow at this angle, which changes the response of the sensor to render it most sensitive around very small fields. The voltage is strongest when the sensors point north and weakest when they point south." The researchers conducted outdoor experiments to demonstrate that their idea works in practical settings.
With a sensor attached to his index finger, the user started out from the north, first heading west, then south and back again -- causing the voltage to rise and fall again accordingly. The cardinal directions that were displayed matched those shown on a traditional compass used as a reference. "This shows that we were able to develop the first soft and ultrathin portable sensor which can reproduce the functionality of a conventional compass and prospectively grant artificial magnetoception to humans," Bermúdez says. But that is not all. The researchers were also able to transfer the principle to virtual reality, using their magnetic sensors to control a digital panda in the computer game engine, Panda3D.
In these experiments, pointing to the north corresponded to a movement of the panda to the left, pointing to the south to a movement to the right. When the hand was on the left, i.e. magnetic north, the panda in the virtual world started moving in that direction. When it swiped in the opposite direction, the animal turned on its heels. "We were able to transfer the real-world geomagnetic stimuli straight into the virtual realm," Denys Makarov summarizes. As the sensors can withstand extreme bending and twisting without losing their functionality, the researchers see great potential for the practical use of their sensors not only as a way to access virtual reality. "Psychologists, for instance, could study the effects of magnetoception in humans more precisely, without bulky devices or cumbersome experimental setups, which are prone to bias the results," Gilbert Santiago Cañón Bermúdez projects.

Comments

Post a Comment

Popular posts from this blog

Dark matter may be older than the Big Bang

Dark matter, which researchers believe make up about 80% of the universe's mass, is one of the most elusive mysteries in modern physics. What exactly it is and how it came to be is a mystery, but a new Johns Hopkins University study now suggests that dark matter may have existed before the Big Bang. The study, published August 7 in  Physical Review Letters , presents a new idea of how dark matter was born and how to identify it with astronomical observations. "The study revealed a new connection between particle physics and astronomy. If dark matter consists of new particles that were born before the Big Bang, they affect the way galaxies are distributed in the sky in a unique way. This connection may be used to reveal their identity and make conclusions about the times before the Big Bang too," says Tommi Tenkanen, a postdoctoral fellow in Physics and Astronomy at the Johns Hopkins University and the study's author. While not much is known about its origins,...
Post a Comment
Read more

All of the starlight ever produced by the observable universe measured

All of the starlight ever produced by the observable universe measured The team's measurement, collected from Fermi data, has never been done before. This map of the entire sky shows the location of 739 blazars used in the Fermi Gamma-ray Space Telescope’s measurement of the extragalactic background light (EBL). The background shows the sky as it appears in gamma rays with energies above 10 billion electron volts, constructed from nine years of observations by Fermi’s Large Area Telescope. The plane of our Milky Way galaxy runs along the middle of the plot. From their laboratories on a rocky planet dwarfed by the vastness of space, Clemson University scientists have managed to measure all of the starlight ever produced throughout the history of the observable universe. Astrophysicists believe that our universe, which is about 13.7 billion years old, began forming the first stars when it was a few hundred million years old. Since then, the universe has become a st...
Post a Comment
Read more

Reflecting antiferromagnetic arrangements

Reflecting antiferromagnetic arrangements : Brookhaven Lab physicists Claudio Mazzoli (left) and Mark Dean at the Coherent Soft X-ray Scattering (CSX) beamline at the National Synchrotron Light Source II. Mazzoli and Dean are part of the team of scientists led by Rutgers University that used the CSX beamline to image some magnetic domains in an iron-based 'antiferromagnetic' material. The ability to image these domains is key to developing spintronics, or spin electronics, for practical applications. A team led by Rutgers University and including scientists from the U.S. Department of Energy's (DOE) Brookhaven National Laboratory has demonstrated an x-ray imaging technique that could enable the development of smaller, faster, and more robust electronics. Described in a paper published on Nov. 27 in  Nature Communications , the technique addresses a primary limitation in the emerging research field of "spintronics," or spin electronics, using magneti...
Post a Comment
Read more