Maro Publications

Actuators

Notes

*5/10/2013
from 9/23/2012

Maro Topics

Comments

Patent Abstracts

Patent Titles

 

Applications

Electroactive Polymer Applications

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Notes

1. “In engineering, actuators are a subdivision of transducers. They are devices which transform an input signal (mainly an electrical signal) into motion. Electrical motors, pneumatic actuators, hydraulic pistons, relays, comb drives, piezoelectric actuators, thermal bimorphs, digital micromirror devices and electroactive polymers are some examples of such actuators. Motors are mostly used when circular motions are needed, but can also be used for linear applications by transforming circular to linear motion with a bolt and screw transducer. On the other hand, some actuators are intrinsically linear, such as piezoelectric actuators. In virtual instrumentation actuators and sensors are the hardware complements of virtual instruments. Computer programs of virtual instruments use motion into linear motion, or vice versa. Conversion is commonly made via a few simple types of mechanism including:

Screw: Screw jack, ball screw and roller screw actuators all operate on the principle of the simple machine known as the screw. By rotating the actuator's nut, the screw shaft moves in a line. By moving the screw shaft, the nut rotates.

Wheel and axle: Hoist, winch, rack and pinion, chain drive, belt drive, rigid chain and rigid belt actuators operate on the principle of the wheel and axle. By rotating a wheel/axle (e.g. drum, gear, pulley or shaft) a linear member (e.g. cable, rack, chain or belt) moves. By moving the linear member, the wheel/axle rotates.

In engineering, actuators are frequently used as mechanisms to introduce motion, or to clamp an object so as to prevent motion. In electronic engineering, actuators are a subdivision of transducers. They are devices which transform an input signal (mainly an electrical signal) into motion. Specific examples include: electrical motors, pneumatic actuators, hydraulic actuators, linear actuators, comb drive, piezoelectric actuators and amplified piezoelectric actuators, thermal bimorphs, micromirror devices and electroactive polymers.

Motors are mostly used when circular motions are needed, but can also be used for linear applications by transforming circular to linear motion with a bolt and screw transducer. On the other hand, some actuators are intrinsically linear, such as piezoelectric actuators.

"Force fighting" can occur when two or more actuators provide conflicting inputs to the mechanism.

 (Wikipedia, Actuators, 9/23/2012)

2. “Polymer materials capable of converting electrical energy into mechanical energy and/or of converting mechanical energy into electrical energy (referred to herein as being electroactive) have been reported to be potentially interesting alternatives to common actuator technologies, such as electromagnetic motors, piezoelectric ceramics and solenoids.

US application 2004/0263028 relates to a transducer comprising a electroactive polymer selected from polymers based on homopolymerisable monoethylenically unsaturated monomers, thermoplastic elastomers and silicone based polymers. The actually described polymers tend to be relatively stiff (high E-modulus), are based on apolar mononomers and/or have a relatively low electrical dielectric constant (.di-elect cons.). This puts limits to their processibility and/or their electroactive properties.”

[Boersma, US Patent 8,258,238 (9/4/2012)]

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Interested!!
Bookmark this page to follow future developments!.
(RDC 6/5/2012)

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Roger D. Corneliussen
Editor
www.maropolymeronline.com

Maro Polymer Links
Tel: 610 363 9920
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E-Mail: cornelrd@bee.net  

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Copyright 2012 by Roger D. Corneliussen.
No part of this transmission is to be duplicated in any manner or forwarded by electronic mail without the express written permission of Roger D. Corneliussen
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* Date of latest addition; date of first entry is 9/23/2012.