Session: 03-13-01: Multifunctional Electronics and Energy Devices

Paper Number: 100245

100245 - Computational Modeling of Polymer Flexoelectric Materials in Energy Harvesting Applications 

The flexoelectric effect, similar to the piezoelectric effect, is a coupling of the electrical and mechanical responses of a material. Unlike the piezoelectric effect it operates off of an asymmetry in the deformation rather than an asymmetry in the material. It is a coupling between the electric field and strain gradient rather than the strain itself. This allows the flexoelectric effect to be present in a wider variety of materials including metals, ceramics, and polymers. Such a coupling facilitates for energy transfer between the electrical and mechanical domains. This energy transfer can be used in sensing, actuation, vibrational damping, among other applications. For example one can utilize it to create flexoelectric micro-generators for energy harvesting. To that end soft materials are a good choice due to large elastic deformations, relatively low elastic modulus, and ease of fabrications. The low elastic modulus lowers the amount of mechanical energy input required for an electrical output. The large deformations allow more complicated gradients to form. As well as, the ease of manufacture makes a test geometry easier to verify experimentally. As the flexoelectric effect works off asymmetry in the deformation, the geometry and loading of the subject is an important factor in the electrical response. It is therefore prudent to ask what the optimal geometry for a flexoelectric micro-generator is. In this study, we are investigating the methodology for modeling and topological optimization of a flexoelectric micro-generator in a contact situation as well as uncertainty qualification of simulation results. To optimize such a model the mechanical and electrical response of a test geometry must be readily obtainable. To obtain this response finite element method augmented by isogeometric analysis is used to approximate the electrical and mechanical behavior of the test geometry given the contact surface and loading of the flexoelectric micro-generator. Isogeometric analysis augmented basis functions are utilized to streamline the geometric parameterization of the model and produce a more robust simulation. From this field result a functional was selected to be used as the objective function. The boundary conditions, parameterization, and functional are being chosen to take into account ease of replication in lab conditions, experimental setup, manufacturability, and ease of measurements for experimental validations. Standard topological optimization methods can then be used to find the optimal geometry given the model and uncertainty qualification can be used to determine the reliability of said geometries response. Finally, the above process can be synthesized into a workflow for setting up a model, parameterization, and optimizing geometries for multi-functional applications.

Presenting Author: Daniel Roskuski University of Massachusetts Dartmouth

Presenting Author Biography: master's student studying mechanical engineering at the University of Massachusetts Dartmouth. specializing in simulations.

Authors:

Daniel Roskuski University of Massachusetts Dartmouth
Caiwei Shen University of Massachusetts Dartmouth
Jun Li University of Massachusetts Dartmouth