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Electromechanical Properties of 3D Multifunctional Nano-Architected Materials


Lifson, Max Louis (2019) Electromechanical Properties of 3D Multifunctional Nano-Architected Materials. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/D0AD-4T88.


In this thesis, we explore the fabrication and characterization of 3D architected multifunctional materials in three different categories: varied density for tailored mechanical response, stiff ultra low-k dielectric materials, and direct laser writing of piezoelectric structures at the micron scale. The density of an architected material plays a large role in determining its effective Young’s modulus, strength, and deformation behavior. The first section of this work explores the effect of incorporating two density regions into hollow nanolattices, which results in two distinct mechanical response regions for horizontal interfaces and a combined varying response for a diagonal interface. The second section of this work describes low dielectric constant (low-k) materials, which have gained increasing popularity because of their critical role in developing faster, smaller, and higher performance devices. We report the fabrication of 3D nanoarchitected hollow-beam alumina dielectrics with a k value of 1.06 - 1.10 at 1 MHz that is stable over the voltage range of -20 to 20 V and a frequency range of 100 kHz to 10 MHz, with an effective Young’s modulus of 30 MPa, a strength of 1.07 MPa, a nearly full shape recoverability to its original size after >50% compressions, and outstanding thermal stability with a thermal coefficient of dielectric constant (TCK) of 2.43 x 10-5K-1 up to 800° C. Finally, we report the fabrication of monolithic piezoelectric ZnO structures of arbitrary shape via a polymer complex route. We have confirmed the microstructure using XRD, TEM, and SAED, and have observed its electromechanical response using a novel in-situ experiment.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Electromechanical; architected materials; multifunctional materials; low-k dielectric; varied density; piezoelectric; nanoscale
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Materials Science
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Greer, Julia R.
Thesis Committee:
  • Faber, Katherine T. (chair)
  • Johnson, William Lewis
  • Burdick, Joel Wakeman
  • Greer, Julia R.
Defense Date:13 December 2019
Funding AgencyGrant Number
GIST-Caltech Collaborative Research CG2016
Record Number:CaltechTHESIS:01182019-105653047
Persistent URL:
Related URLs:
URLURL TypeDescription Adapted for Ch. 4 Videos
Lifson, Max Louis0000-0002-0382-182X
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:11347
Deposited By: Max Lifson
Deposited On:20 Feb 2019 20:33
Last Modified:08 Nov 2023 00:27

Thesis Files

PDF (Complete Thesis) - Final Version
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