Transcript
One of the most promising commercial technologies of the decade is
"additive manufacturing." Recently, printers have advanced to the
point that they can even print sensors and electronic components on 2-D and 3-D
substrates. And new, robot-assisted production line technology now allows the
process to be automated.
How does it work? The tiny resistors, transistors, circuit paths,
and capacitors are first designed on-screen and then deposited directly onto
two- and three-dimensional substrates, like circuit boards.
The printing is done with so-called "functional inks,"
which are electronic materials in liquid or paste form. Potential applications
for these printed electronics range from electronic circuits in digital
thermometers, to flexible sheets of solar cells, to smart packaging with
built-in sensors.
To automate the process of applying printed electronics to
components with flat and three-dimensional surfaces, scientists have set up a
robot-assisted production line that allows different printing methods to be
combined in a single run.
Modules for silk-screen, inkjet, dispenser, and aerosol-jet
printing are integrated into the production unit. The production line, with its
central robotic unit, component feeders, printing systems, and heat treatment
furnaces, enables them to functionalize surfaces on a near-industrial scale.
The availability of different technologies in one system makes it
possible to print structures of different surface areas, widths, and
thicknesses on the substrate.
For example, aerosol-jet printing enables the researchers to
deposit extremely fine structures, with a width of only 10 micrometers, onto
the component. In this non-contact process, the conductive ink is transformed
into an aerosol using pneumatic spraying, and then fed to the print head
through a fine tube.
The print head focuses the aerosol jet on the surface of the
substrate, which doesn't necessarily have to be flat or smooth - even curved
surfaces can be printed on with this method. It is also possible to vary the
thickness of the printed features and create multi-layer structures. For
example, the system can lay down circuits on a circuit board, and provide it
with a corrosion-resistant coating.
The choice of materials that can be used as substrates or
functional inks is almost unlimited. And the robot-assisted production line
also helps to shorten development lead times.
In the past, to provide components with sensor functions, it was
often necessary to integrate the sensors in the component after it had been
manufactured - a time-consuming process. Depending on the application, the
researchers can achieve the same result in a matter of seconds or minutes by
printing fully functionalized components.
This offers advantages to many sectors of industry, including
automobile manufacturing and aerospace, as well as microsystems engineering.
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