Philippe Metz

Publications (2)2.09 Total impact

• Article: A methodology towards geometry optimization of high performance polypyrrole (PPy) actuators

  Gürsel Alici, Philippe Metz, Geoffrey M Spinks
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  ABSTRACT: This paper focuses on a geometry optimization methodology based on a lumped-parameter mathematical model, which accepts the voltage as the input, and bending angle and bending moment as the outputs, for a trilayer bending-type polymer actuator. An analogy is made between thermal strain and the real strain in the actuator to establish the mathematical model, which is solved using the finite element method in order to obtain theoretical results. The polypyrrole (PPy) actuator, which consists of five layers of three different materials, operates in a non-aquatic medium, i.e., air, as opposed to its predecessors. With reference to its operation principle, the movement or propagation of dopant ions and solvent molecules into the PPy layers is mimicked with a temperature distribution model to improve the accuracy of the model. Theoretical and experimental results presented suggest that the model is valid to predict the bending angle and bending moment outputs of the PPy actuators quite well for a range of input voltages and actuator thicknesses. The model has been employed to determine the actuator geometry, resulting in improved/higher bending angle and bending moment outputs. The geometry optimization results for an actuator with a constant length and width demonstrate that the thicker is the root of the actuator, where it is clamped, the higher is the bending moment, as compared to an actuator with a uniform thickness.
  Smart Materials and Structures 01/2006; 15(2):243. · 2.09 Impact Factor
• Article: A finite element model for bending behaviour of conducting polymer electromechanical actuators

  Philippe Metz, Gürsel Alici, Geoffrey M. Spinks
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  ABSTRACT: Emerging conducting polymer electromechanical actuators (CPEA) have many potential applications ranging from biomedical to micro/nano manipulation systems. In order to make use of their potential, it is needed to establish a valid mathematical model to provide enhanced degrees of understanding, predictability, control and efficiency in performance. Although it is known that the mechanism behind their operation is quite straightforward; establishing a mathematical model to predict their behaviours and quantify their performance is hampered by many mechanical, electrical and chemical parameters. With this in mind, the aim of this study is to establish and experimentally validate a lumped-parameter model of bending-type polypyrrole (PPy) actuators for use in improving their displacement and force outputs. With reference to their operation principle, we draw an analogy between the thermal strain and the real strain in the PPy actuators due to the volume change to set up the mathematical model, which is a coupled structural/thermal model. The finite element method (FEM) is used to solve the model. The effect of propagation of the ion migration into the PPy layers is mimicked with a temperature distribution model. Theoretical and experimental results demonstrate that the model is practical and effective enough in predicting the bending angle and bending moment outputs of the PPy actuators quite well for a range of input voltages, and the PPy layer thicknesses.
  Sensors and Actuators A: Physical.