A research team from the Johannes Kepler University in Linz and the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) has created the world’s first electronic sensor by ingeniously using magnetic fields. The sensor has the ability to simultaneously process both tactile and touchless stimuli.
Previous efforts to date have failed to integrate these aspects on a single device because of overlapping signals of the numerous stimuli. The sensor can be readily applied to the human skin, thus offering a smooth interactive platform for both augmented and virtual reality conditions. The scientists have reported the study outcomes in the Nature Communications scientific journal.
The skin is the largest human organ and is probably the most functionally multifaceted portion of the body. It is capable of differentiating between the most diverse stimuli very quickly and also classifying the intensity of signals across a wide range.
A research group headed by Dr Denys Makarov from HZDR’s Institute of Ion Beam Physics and Materials Research and also the Soft Electronics Laboratory headed by Professor Martin Kaltenbrunner at Linz University was able to create an electronic equivalent that had similar properties.
The novel sensor can considerably streamline the interaction between machines and humans, claimed the researchers.
Applications in virtual reality are becoming increasingly more complex. We therefore need devices which can process and discriminate multiple interaction modes.
Denys Makarov, Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf
However, the existing systems operate either by tracking objects in a touchless way or by simply registering a physical touch. Now, for the first time, both interaction pathways have been integrated into the new sensor, which the scientists refer to as “magnetic microelectromechanical system” (m-MEMS).
Our sensor processes the electrical signals of the touchless and the tactile interactions in different regions. And in this way, it can differentiate the stimuli’s origin in real time and suppress disturbing influences from other sources.
Dr Jin Ge, Study First Author, Helmholtz-Zentrum Dresden-Rossendorf
The basis of this research is the extraordinary design worked out by the researchers.
Flexibility on All Surfaces
The researchers initially created a magnetic sensor on a thin polymer film. The sensor depends on the so-called Giant Magneto Resistance (GMR). The polymer film, in turn, was closed by a silicon-based polymer layer (polydimethylsiloxane) comprising a round cavity developed to align precisely with the sensor. Within this void, the scientists incorporated a flexible permanent magnet that had pyramid-like tips sticking out from its surface.
“The result is rather more reminiscent of cling film with optical embellishments,” commented Makarov. “But this is precisely one of our sensor’s strengths.”
This is how the sensor continues to be so extraordinarily flexible—it fits into all the settings perfectly. The sensor can work even under curved conditions without losing its functionality. Thus, it can be placed quite easily, for instance, on the fingertip.
The researchers tested their development in this same, exact way. Jin Ge elaborated that “On the leaf of a daisy we attached a permanent magnet, whose magnetic field points in the opposite direction of the magnet attached to our platform.”
When the finger approaches this external magnetic field, a change occurs in the electrical resistance of the GMR sensor—in other words, it drops. This takes place until the point when the finger truly makes contact with the leaf. During this time, it increases suddenly because the integrated permanent magnet is pressed more proximally to the GMR sensor and, as a result, superimposes the external magnetic field.
“This is how our m-MEMS platform can register a clear shift from touchless to tactile interaction in seconds,” stated Jin Ge.
Click Instead of Click, Click, Click
This enables the sensor to selectively regulate both virtual and physical objects, as demonstrated by one of the experiments carried out by the scientists—the physicists projected virtual buttons on a glass plate with which they developed a permanent magnet, where the buttons manipulate real conditions like the brightness or room temperature.
The researchers used a finger on which the “electronic skin” was applied to first choose the required virtual function touchless by interacting with the permanent magnet. Once the finger made contact with the plate, the m-MEMS platform automatically changed to the tactile interaction mode. Heavy or light pressure can be subsequently utilized, for instance, to either increase or decrease the room temperature accordingly.
The scientists simplified an activity that had earlier needed many interactions to one that now needed just one interaction.
This may sound like a small step at first. In the long-term, however, a better interface between humans and machines can be built on this foundation.
Martin Kaltenbrunner, Professor, Linz University
Apart from virtual reality spaces, this “electronic skin” can also be used, for example, in sterile settings. The sensors can be used by surgeons to manage medical instruments without touching them during a process. Such an approach can reduce the risk of contamination.