Polypyrrole actuators: modeling and performance

John David Madden; Peter Geoffrey Madden; Ian Warwick Hunter

doi:10.1117/12.432688

16 July 2001 Polypyrrole actuators: modeling and performance

John David Madden, Peter Geoffrey Madden, Ian Warwick Hunter

Proceedings Volume 4329, Smart Structures and Materials 2001: Electroactive Polymer Actuators and Devices; (2001) https://doi.org/10.1117/12.432688
Event: SPIE's 8th Annual International Symposium on Smart Structures and Materials, 2001, Newport Beach, CA, United States

Abstract

Conducting polymer actuators generate forces that exceed those of mammalian skeletal muscle by up to two orders of magnitude for a given cross-sectional area, require only a few volts to operate, and are low in cost. However application of conducting polymer actuators is hampered by the lack of a full description of the relationship between load, displacement, voltage and current. In an effort to provide such a model, system identification techniques are employed. Stress-strain tests are performed at constant applied potential to determine polypyrrole stiffness. The admittance transfer function of polypyrrole and the associated electrolyte is measured over the potential range in which polypyrrole is highly conductive. The admittance is well described by treating the polymer as a volumetric capacitance of 8*10⁷ F*m³ whose charging rate is limited by the electrolyte resistance and by diffusion within polypyrrole. The relationship between strain and charge is investigated, showing that strain is directly proportional to charge via the strain to charge density ratio, (alpha) = 1*10+-10 m³*C^-1, at loads of up to 4 MPa. Beyond 4 MPa the strain to charge ratio is time dependent. The admittance models, stress/strain relation and strain to charge relationship are combined to form a full description of polypyrrole electromechanical response. This description predicts that large increases in strain rate and power are obtained through miniaturization, yielding bandwidths in excess of 10 kHz. The model also enables motor designers to optimize polypyrrole actuator geometries for their applications.

Citation Download Citation

John David Madden, Peter Geoffrey Madden, and Ian Warwick Hunter "Polypyrrole actuators: modeling and performance", Proc. SPIE 4329, Smart Structures and Materials 2001: Electroactive Polymer Actuators and Devices, (16 July 2001); https://doi.org/10.1117/12.432688

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available