Von: Marc Voigt via ak discourse
Datum: Fri, 29 Mar 2019
Betreff: [ak-discourse] Forschungskolloquium
Liebe Kollegen und Studierende, liebe Interessenten an Veranstaltungen
am Fachgebiet Audiokommunikation,
hiermit möchte ich Sie sehr herzlich zu unserem Forschungskolloquium
am kommenden Dienstag (02.04., 16.15Uhr) im Raum EN 324 einladen. Im
Rahmen dieses Termins wird Michael Gareis seine Masterarbeiten präsentieren.
Michael Gareis
# Acoustical Behaviour of Buckling Dielectric Elastomer Actuators
Dielectric elastomers (DE) are regarded as a potentially alternative to
conventional actuator technologies. They feature low weight, high
strains and low material costs. A soft dielectric (here: silicone) is
sandwiched between two compliant electrodes. Upon voltage, the material
compresses in thickness and expands in area due to incompressibility.
Their scope of application ranges from sensors, energy generators, smart
textiles to biomimetic robots and much more. A few concepts of
loudspeakers using DE have been demonstrated by the research community.
One of the disadvantages of previously concepts was the need for
mechanical bias (e.g. by air pressure). This work proposes a new concept
of loudspeaker, which does not need prestretch or other means of
mechanical bias. Buckling dielectric elastomer actuators use the area
expansion of actuated DE to buckle up. This mechanism is used to
construct a milli-meter-scale loudspeaker with good frequency response
in the range above 5 kHz.
The concept is implemented using automatically fabricated multi-layer
membranes of 3 to 8 layers. The multilayer structure allows to generate
more force and higher flexural rigidity than a single-layer setup. 6
samples with different amount of layers and a diameter of 8 mm are
fabricated.
A full analytical model is derived. Measurements of the static
deflection, the frequency response and the total harmonic distortion
validate the model. Ways of optimizing and tuning the loudspeaker are
discussed in the latter part of the thesis.
Sound pressure level increases with 18 dB/octave until the peak SPL of
almost 80 dB (in 1 m distance in half-space) is achieved at a frequency
of 5 kHz. The small scale of the speaker allows it to be installed in
large arrays and thus might offer a hardware platform for
high-resolution beam forming or wave field synthesis.
Viele Grüße
Marc Voigt
—
Marc Voigt
IT-Administration
Technische Universität Berlin
Fakultät I – Geistes- und Bildungswissenschaften
Institut für Sprache und Kommunikation
Fachgebiet Audiokommunikation
Faculty I Humanities
Institute of Speech and Communication
Audio Communication Group
Einsteinufer 17c, 10587 Berlin
GERMANY
Telefon: +49 (0)30 314-25557
Telefax: +49 (0)30 314-21143
marc.voigt@tu-berlin.de