Equivalent Bimorph Beam Model for IPMC Actuators

1 Equivalent Bimorph Beam Model for IPMC Actuators 

To predict the behaviour of IPMC diaphragms, the equivalent bimorph beam model, whieh was recently introduced by Lee et al. [28], is adopted in this study. Here, the key ideas of the model are summarized. 

Substituting the experimentally measured tip displacement into Equation (9.2), dsj can be obtained for a given input voltage. In the equivalent bimorph beam model, the Young s modulus E) contributing to the bending stiffness of an IPMC is determined from the blocking force Equation (9.3) of a bimorph beam  

To determine the equivalent of Young s modulus ( ), Equation (9.3) is rewritten as  

For all numerical analyses, a commercial finite element analysis program, MSC/ NASTRAN [29], was used in conjunction with the equivalent bimorph beam model. A thermal analogy technique proposed by Taleghani and Campbell [30] was used to implement the electromechanical coupling effect into the finite element model. In the thermal analogy technique, the electromechanical coupling coefficient (dj/) is converted into the thermal expansion coefficient a/ as follows  

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In this chapter, we have described an IPMC-driven infusion micropump for recent biomedical applications. Even though the applieations of IPMCs for biomedical fields require more trials and development methods, IPMCs are still attractive materials due to their electromechanical and mechanoelectric properties. A systematic design method of an IPMC-driven micropump was introduced. In order to properly estimate the deformed shapes of IPMC diaphragms, the equivalent bimorph beam model for IPMC actuators was conveniently used, in conjunction with the finite element method. 

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