Electronic skin anticipates and perceives touch from different directions for the first time
rael-science
Electronic skin anticipates and perceives touch from different directions for the first time
by Chemnitz University of Technology
A
research team from Chemnitz and Dresden has taken a major step forward
in the development of sensitive electronic skin (e-skin) with integrated
artificial hairs. E-skins are flexible electronic systems that try to
mimic the sensitivity of their natural human skin counterparts.
Applications range from skin replacement and medical sensors on the body
to artificial skin for humanoid robots and androids. Tiny surface hairs
can perceive and anticipate the slightest tactile sensation on human
skin and even recognize the direction of touch. Modern electronic skin
systems lack this capability and cannot gather this critical information
about their vicinity.
A
research team led by Prof. Dr. Oliver G. Schmidt, head of the
Professorship of Material Systems for Nanoelectronics as well as
Scientific Director of the Research Center for Materials, Architectures
and Integration of Nanomembranes (MAIN) at Chemnitz University of
Technology, has explored a new avenue to develop extremely sensitive and
direction-dependent 3D magnetic field sensors that can be integrated into an e-skin system
(active matrix). The team used a completely new approach for
miniaturization and integration of 3D device arrays and made a major
step towards mimicking the natural touch of human skin. The researchers have reported their results in the current issue of the journal Nature Communications.
Christian
Becker, Ph.D. student in Prof. Schmidt's research group at MAIN and
first author of the study says that their "approach allows a precise
spatial arrangement of functional sensor elements in 3D that can be
mass-produced in a parallel manufacturing process. Such sensor systems
are extremely difficult to generate by established microelectronic
fabrication methods."
New approach: Elegant origami technology integrates 3D sensors with microelectronic circuitry
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 precisely 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 a variety of 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 small space and arrange them in a geometry that is not achievable
by any conventional microfabrication technologies. "Micro-origami
processes were developed more than 20 years ago, and it is wonderful to
see how the full potential of this elegant technology can now be
exploited for novel microelectronic applications," says Prof. Oliver G.
Schmidt.
The
research team integrated the 3D micro-origami magnetic sensor array
into a single active matrix, where each individual sensor can be
conveniently addressed and read-out by microelectronic circuitry. "The
combination of active-matrix magnetic sensors with self-assembling
micro-origami architectures is a completely new approach to miniaturize
and integrate high-resolution 3D sensing systems," says Dr. Daniil
Karnaushenko, who contributed decisively towards the concept, design and
implementation of the project.
Tiny hairs anticipate and perceive direction of touch in real time
The research team has succeeded in integrating the 3D magnetic field sensors with magnetically rooted fine hairs into an artificial e-skin.
The e-skin is made of an elastomeric material into which the
electronics and sensors are embedded—similar to organic skin, which is
interlaced with nerves.
When the hair is
touched and bends, the movement and exact position of the magnetic root
can be detected by the underlying 3D magnetic sensors. The sensor
matrix is therefore not only able to register the bare movement of the
hair, but also determines the exact direction of the movement. As with
real human skin, each hair on an e-skin becomes a full sensor unit that
can perceive and detect changes in the vicinity. The magneto-mechanical
coupling between 3D magnetic sensor and magnetic hair root in real-time
provides a new type of touch-sensitive perception by an e-skin system.
This capability is of great importance when humans and robots work
closely together. For instance, the robot can sense interactions with a
human companion well in advance with many details just before an
intended contact or an unintended collision is about to take place.
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