Date of Completion

8-17-2018

Embargo Period

2-13-2019

Keywords

modulus of resilience; polymer nanocomposite; mechanical properties; in-situ; elastic strain energy

Major Advisor

Seok-Woo Lee

Associate Advisor

George Rossetti

Associate Advisor

Avinash Dongare

Associate Advisor

Puxian Gao

Associate Advisor

Ying Li

Field of Study

Materials Science and Engineering

Degree

Doctor of Philosophy

Open Access

Open Access

Abstract

The storage, and subsequent release, of mechanical potential energy during the deformation of a material is an important phenomenon that allows for the working principles of engineered spring devices to be realized. The recovery of the released mechanical potential energy, stored as atomic configurational changes, can be utilized and harnessed to perform work on an element in the surrounding environment. This interplay between storage and release of mechanical potential energy in materials plays important roles not only in the engineering of advanced “spring” devices such as sporting equipment and resonators in microelectromechanical systems (MEMS) devices but also in the fast and high-powered locomotion of many animals. Furthermore, mechanical potential energy could be utilized in emerging technologies such as alternative energy systems as well as artificial muscle for robotic movements and motion.

Modulus of resilience is the measure of a material’s ability to store and release elastic strain energy prior to plastic yielding and is highly dependent upon the strength and the Young’s modulus of a material. It is desirable to have high strength and low Young’s modulus to obtain high modulus of resilience. In general, designing a material with enhanced modulus of resilience is not straightforward; this is because of the mutual scaling relationship present between strength and Young’s modulus. It is therefore, necessary to consider and develop a novel fabrication method in which a material with high mechanical strength and a compliant Young’s modulus can be realized.

In this dissertation, we develop a novel synthesis technique to realize high-strength, compliant polymer nanocomposite; offer a fundamental design principle to fabricate polymer nanocomposite with high modulus of resilience based on micromechanical models and demonstrate application to three-dimensional architectured systems where enhancement of the modulus of resilience of microlattices are discussed.

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