Transcript
CONDUCTING POLYMER ACTUATORS
Pagilagan, Evan Mart P.
What is a Conducting polymer? Are organic polymers that conduct electricity. Generally not plastics. Can offer high electrical conductivity but do not
show mechanical properties as other commercially used polymers do.
The electrical properties can be fine-tuned using the methods of organic synthesis and by advanced dispersion techniques.
Types of Conducting Polymers
Ionic Conductive Actuator- soft, small, and lightweight.- is flexible, made of polymer and metallic materials.- low voltage requirement, only 2V.
The actuator element- motion can be controlled electrically.- soft as muscles.- light.- doesn’t generate sound upon operation.- Creation of the drive device from 0.1 mm to 10mm is
possible.- combination of element results in living thing like movement.
- Power consumption is able to move few for a long time.- Although it is driven in water fundamentally, a drive in air is also possible by the design of containing water.
In air operation. Robot Hand
Conducting Polymer Actuator- expand and shrink with doping and dedoping.- electrochemically driven for actuation.- polyacetylene, polypyrrole, polyphenylene, Polythiophene, Polyaniline, Poly(phenylene vinylene).
Polypyrrole (PPy)– conductive polymer- oxidation-reduction reaction when voltage is
applied- redox induces ion flow into or out of polymer- flow in = expansion- requires electrolyte
Performance for PPy bilayer actuator- strain: 12.4%- energy density: 0.040 J/g- speed: <1Hz - output pressure: 22 MPa- drive voltage: +/- 1V
“Wet” versus “Dry” actuation
“Wet” – Ionic actuators. Utilize mobility or diffusion of ions. polymer-metal composites conductive polymers others . . .
“Dry” – Electronic actuators. Utilize Coulomb forces. dielectric elastomers electrostrictive polymers others . . .
Electrostricted Polymers
Electrostricted graft elastomers motion achieved through electrostriction applied electric field induces a change from
one polarized direction to another, or one phase to another.
flexible backbone
polarized chain
Dielectric Elastomers
elastomer film is sandwiched between compliant electrodes
apply electric field: E = V/m Maxwell pressure: p = ee0E2
electrodes squeeze elastomer in thickness
V+apply voltage
Dielectric Elastomers
materials available off-the-shelf- 3M VHB acrylic tape- various silicone elastomers
desired features- high dielectric constant and breakdown strength- low elastic modulus – high % elongation- thin film
Dielectric Elastomers
Increase performance through prestrain- stretch elastomer film in one planar direction- fix motion in prestrained direction- allow expansion in other planar direction during
activation
V+
1 2 3 4
dielectric elastomer
electrode
rigid constraints
Dielectric Elastomers
Performance- strain: >200%- energy density: 0.75 – 3.4 J/cm3
- speed: 10Hz - 20kHz- output pressure: 3.0 – 7.2 MPa- drive voltage: 5kV
ACTUATOR COMPARISON
REFERENCES
http://en.wikipedia.org/wiki/Conductive_polymer
http://www.eamex.co.jp/tech_e.html http://www.eamex.co.jp/denshi_hp/
english/denshi_idex_e.htm web.me.com/daloy/LOY...Site/Polymer.../
conducting%20polymers.ppt www.cs.berkeley.edu/~jfc/DR/F03/
lectures/lec15/lec15.ppt