4 3 5 Result synTheTIc MIcro fILaMenTs for use as sensors · microfilaments with a diameter of...
Transcript of 4 3 5 Result synTheTIc MIcro fILaMenTs for use as sensors · microfilaments with a diameter of...
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101Fraunhofer Institute for Laser Technology ILT, www.ilt.fraunhofer.de
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4U-shapedmicrofilaments.
5 Illuminated, radially symmetrical
microfilamentarrays.
Result
Arrays of filaments of different geometries and lengths were
produced using the method described. Two examples are illus-
trated above. Fig. 5 shows radially symmetrical microfilament
arrays in which the individual filaments have a diameter of
100 μm and a length of 1 mm. Fig. 4 shows filaments with
a U-shaped cross-section. The different geometries result in
microfilaments with different bending and breaking strengths.
applications
Synthetic microfilaments can be used in combination with
suitable piezoelectric devices as tactile sensors. Radially
symmetrical microfilament arrays, for instance, can be used
in medical devices to detect and diagnose stenosis and arterial
insufficiency. Another area of application for microfilaments
is flow testing, where flow characteristics can be established
by measuring the deflection of the filaments.
contacts
Dipl.-Phys. Moritz Schaefer
Phone +49 241 8906-305
Dr. Arnold Gillner
Phone +49 241 8906-148
task
Microfilaments are commonly found in nature. Many animals
use them as sensors to obtain information on their environ-
ment. Grasshoppers, for example, have microscopic hairs on
their backs measuring up to 1 mm in length, which they use
to sense the direction of low-frequency noises. In order to
develop technical applications that mimic this highly efficient
sensor concept, there is a need for a method of fabricating
microfilaments with a diameter of between 20 and 100 μm
and a length of up to 1 mm.
Method
The microfilaments are cast in polycarbonate molds in which
microscopic holes have been drilled using an excimer laser.
The use of a mask-projection laser ablation technique enables
a wide variety of hole geometries, and hence filament geo-
metries, to be produced by selecting appropriate mask layouts.
To fabricate the microfilaments, polydimethylsiloxane (PDMS,
a silicone compound) is poured into the mold, hardened,
and peeled off. Since the mold is not destroyed by this
process, it can be reused.
synTheTIc MIcro fILaMenTs for use as sensors
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