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NTU Nano-BioMEMS Group-2-
C. L. Kuo, NTU ESOE
Outline
Introduction
A Soft and dexterous motor
- Abstract- Rotary motion
- Result
- Conclusion Application
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NTU Nano-BioMEMS Group-3-
C. L. Kuo, NTU ESOE
Dielectric elastomers (DEs) are smart material systems which produce
large strains (up to 300%) and belong to the group of electroactive
polymers(EAP). Based on their simple working principle dielectric elastomer
actuators (DEA) transform electric energy directly into mechanical work. DEare lightweight, have a high elastic energy density and are investigated since
the late 90s. Many potential applications exist as prototypes. Every year in
spring a SPIE conference takes place in San Diego where the newest research
results concerning DEA are exchanged.
= 0
2
2
From Wikipedia
Dielectric elastomers (1)
http://en.wikipedia.org/wiki/Smart_materialhttp://en.wikipedia.org/wiki/Strain_(materials_science)http://en.wikipedia.org/wiki/Electroactive_polymershttp://en.wikipedia.org/wiki/Electroactive_polymershttp://en.wikipedia.org/wiki/Electroactive_polymershttp://en.wikipedia.org/wiki/Electroactive_polymershttp://en.wikipedia.org/wiki/Electroactive_polymershttp://en.wikipedia.org/wiki/Strain_(materials_science)http://en.wikipedia.org/wiki/Smart_materialhttp://en.wikipedia.org/wiki/Smart_materialhttp://en.wikipedia.org/wiki/Smart_material8/3/2019 149 20110518 Dielectric Elastomer
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NTU Nano-BioMEMS Group-4-
C. L. Kuo, NTU ESOE
Dielectric elastomers (2)
Ref. 2003.11
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NTU Nano-BioMEMS Group-5-
C. L. Kuo, NTU ESOE
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NTU Nano-BioMEMS Group-6-
C. L. Kuo, NTU ESOE
Abstract
This paper present a soft, bearing-free artificial muscle
motor that can't only turn a shaft but also reposition it
through a flexible gear.
One actuator technology with performance metrics similar
to natural muscle is the dielectric elastomer actuator(DEA).
When a voltage is applied, the charge accumulating on the
electrode faces gives rise to an electrostatic Maxwell
pressure that results in out-of-plane compression and in-
plane expansion, and that can produce active strains
greater than 30%.
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C. L. Kuo, NTU ESOE
Rubbery motor creates rotary motion (1)
A photo showing two membrane motors supporting a single
shaft. Actuation of electroded zones in the top of the left hand
side membrane and bottom of the right hand membrane (mode
III) repositioned and changed the angle of the shaft.
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C. L. Kuo, NTU ESOE
Rubbery motor creates rotary motion (2)
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C. L. Kuo, NTU ESOE
The rotational speed reduced with rising actuation frequency
The actuation frequency of the wave form, fa, started at 0.4 Hz
and was increased in 0.4 Hz steps up to 3.2 Hz. The voltage
wave form had a lower bound of 0, 500, or 1000 V and an upper
bound of 2500 V.
Above 2.2 Hz the rotor speed reduced. Increasing the lower
voltage limit also reduced the shaft speed, providing a
mechanism for electroactive gear change.
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C. L. Kuo, NTU ESOE
Conclusion
The performance of the DE membrane motor could be
improved with the substitution of a less viscoelastic
elastomer. One material commonly used for DE artificial
muscles is silicone.
Another way to improve the motor is to use lower voltages.
The Maxwell pressure on the membrane is proportional to
the dielectric constant and the square of the electric field.
Using multiple stacked layers of membrane could also be used
to boost torque.
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C. L. Kuo, NTU ESOE
V
Voltage off Voltage on
V
Applications (1)
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C. L. Kuo, NTU ESOE
Thin Film Actuators
Voltage off
Voltage on
Applications (2)
C L K NTU ESOE
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C. L. Kuo, NTU ESOE
Applications (3)
Linear actuators Bending rolls
Push-pull actuators
Speaker
Pump
Sensors
Generator
C L K NTU ESOE
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C. L. Kuo, NTU ESOE
Dielectric elastomer minimum energy structure serpentine
C L K NTU ESOE
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Thank you for your attention!