A research team from the Research Center for Nanomembrane Materials, Architectures and Integration at Chemnitz University of Technology has explored a new avenue to develop extremely sensitive and direction-dependent three-dimensional magnetic field sensors that can be integrated into a e-skin system (i.e. electronic skin ).
The team of researchers used a completely new approach to miniaturization and array integration of 3D devices and took a big step towards mimicking the natural touch of human skin . The scientists say that this new approach enables a precise spatial arrangement of functional 3D sensor elements that can be mass-produced in a parallel manufacturing process. Such sensor systems are extremely difficult to generate by established microelectronic fabrication methods.
Similar to the touch of human skin
The core of the sensor system presented by the research team is a so-called anisotropic magnetoresistance (AMR) sensor. An AMR sensor can be used to accurately determine changes in magnetic fields. AMR sensors are currently used, for example, as speed sensors in cars or to determine the position and angle of moving components in certain machines.
To develop the highly compact sensor system, the researchers took advantage of the so-called micro-origami process. This process is used to fold AMR sensor components into three-dimensional architectures that can resolve the magnetic vector field in three dimensions. Micro-origami allows a large number of microelectronic components to fit into a small space and arrange them in a geometry that cannot be achieved with any conventional microfabrication technology. Microorigami processes were developed more than 20 years ago, and the full potential of this technology can now be exploited for new microelectronic applications such as the development of electronic skin.
The research team integrated the 3D microorigami magnetic sensor array into a single active array, where each individual sensor can be conveniently addressed and read by microelectronic circuitry. “The combination of active matrix magnetic sensors with self-assembling micro-origami architectures is an entirely new approach to miniaturizing and integrating high-resolution 3D sensing systems.
Hairs that anticipate and perceive the direction of touch in real time
The research team also succeeded in integrating the 3D magnetic field sensors with magnetically rooted fine hairs into an artificial electronic skin. The electronic skin is made of an elastomeric material in which electronics and sensors are embedded, similar to organic skin, which is intertwined with nerves.
When the hair is touched and bent, the underlying 3D magnetic sensors can detect the movement and exact position of the magnetic root. Therefore, the sensor array can not only record the bare movement of the hair, but also determine the exact direction of movement.
REFERENCES:
Chemnitz University of Technology.
