Until now, applications of "augmented reality" (virtual reality) have mainly been based on optical methods. Now, physicists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), together with colleagues from the Leibniz Institute for Solid State and Materials Research (IFW) and the Johannes Kepler University Linz (JKU), have developed an ultra-thin, electronic magnetic sensor that can be worn on the skin. The device enables the contactless control of virtual and physical objects solely through interaction with magnetic fields. The wafer-thin film, which clings to the palm of the hand like a second skin and is barely visible to the naked eye, contains sensors that could give people a magnetic sixth sense. In the future, this should enable them to control objects - such as telephones or operating systems - both in the physical world and in augmented or virtual reality environments with mere gestures. At least that's what Dr. Denys Makarov from the Institute of Ion Beam Physics and Materials Research at the HZDR has in mind.

The physicist has now been able to show for the first time that the ultra-thin and flexible magnetic sensors in combination with a permanent magnet can perceive and process changes in a body's position in space. "Our electronic skin records the movements of a hand, for example, by relating its position to the external magnetic fields of the permanent magnet," explains Cañón Bermúdez from HZDR, the first author of the study. "This allows us not only to digitize their rotations and transfer them to the virtual world, but also to influence objects there." In this way, the researchers were able to control a virtual light bulb on a computer screen without touching it.

How it works

To do this, they packed the permanent magnet into a ring-shaped structure. They then divided different angles of their portable sensor to this source into different regions, which in turn corresponded to the light intensity of the light bulb. "By coding the angles between 0 and 180 degrees to correspond to a typical hand movement when dimming a lamp, we created a virtual brightness controller - and controlled it just by moving a hand over the permanent magnet," says Makarov, describing one of the experiments. The researchers were also able to operate a virtual dial in a similar way. According to the Dresden physicists, this could provide an alternative to the connection methods used to date between the physical and augmented or virtual worlds.

"The current systems primarily use optical means to detect moving bodies in order to manipulate virtual objects," explains Makarov. "This requires a large number of cameras and accelerometers on the one hand and fast image data processing on the other. However, the resolution is usually not sufficient to reconstruct even fine movements, such as with the fingers. Due to their bulkiness, conventional gloves and glasses also hinder the experience in virtual reality."

Martin Kaltenbrunner believes that the skin-like sensors could be a better link between man and machine: "Because our polymer films are less than three micrometres thick, they can easily be worn on the body. Just for comparison: a normal human hair is around 50 micrometers thick."

In addition, the skin-like sensors can withstand severe bending and twisting without losing their functionality. According to Oliver G. Schmidt, they are therefore suitable for installation in soft and deformable materials, such as textiles, in order to manufacture wearable electronics. Makarov sees an additional advantage of the new approach over optical systems in the fact that no direct line of sight is required between the object and the sensors. This also opens up potential applications for the security industry. For example, buttons or controls in rooms that cannot be entered due to a hazardous situation could be operated remotely via the sensors.