Award Date

May 2018

Degree Type

Thesis

Degree Name

Master of Science in Engineering (MSE)

Department

Mechanical Engineering

First Committee Member

Kwang Kim

Second Committee Member

Mohamed Trabia

Third Committee Member

Woosoon Yim

Fourth Committee Member

Rebecca Martin

Number of Pages

119

Abstract

Nature is a constant source of inspiration for engineers and scientists through its simple, effective, and elegant solutions to many complex problems. Smart materials and soft robotics have been seen to be particularly well suited for developing biomimetic devices and are active fields of research. In this study, the design, modeling, and optimization of a new biomimetic soft robot is described. Preliminary work was made in the modeling of a biomimetic robot based on the locomotion and kinematics of jellyfish. Modifications were made to the governing equations for jellyfish locomotion that accounted for geometric differences between biology and the robotic design. Particularly, the capability of the model to account for the mass and geometry of the robot design. A simple geometrically defined model is developed and used to show the feasibility of a proposed biomimetic robot. With the concept verified, a more robust physics- based model is developed. In this model, linear beam theory is coupled to an equivalent circuit model to actuate the robot with ionic polymer-metal composite (IPMC) actuators. The circuit model is verified using a robust, Multiphysics finite element model of the IPMC actuator. The newly created physics-based model of the soft robot is compared to that of the geometric model as well as biological jellyfish swimming to highlight its improved efficiency. The design is then optimized using a sequential quadratic programming algorithm for nonlinear multivariable optimization. Standard deviations of the optimized values are used to verify their accuracy, and the propulsion efficiency of the unoptimized and optimized model are compared to verify the improvement in efficiency and overall performance. Scale effects on the optimal design are also examined as an initial form of dimensional analysis. The optimized design shows clear improvement over the unoptimized counterpart, and the modularity of the modeling approach allows for more complex models that include nonlinearities to be easily added.

Keywords

Biomimicry; Ionic Polymer-Metal Composite; Jellyfish; Modeling; Simulation; Soft Robotics

Disciplines

Mechanical Engineering

Language

English


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