Triply Periodic Minimal Surface Lattices for Mechanically Tuning Structures and Designing Multifunctional Devices

On board energy is often limited in robots inhibiting their ability to last for long missions or requiring them to be tethered to a power source. Embodied energy systems store energy throughout structures to increase the energy density of robots. The benefit of such multifunctional structures is that they can perform multiple functions simultaneously. My approach to designing multifunctional structures uses a subcategory of metamaterials called triply periodic minimal surface (TPMS) lattices. These lattices are beneficial for not only mechanically tuning structures but also their large surface area to volume ratio. Large surface area provides a large interaction site that can be leveraged in different energy domains for increased chemical activity, faster diffusion rates, faster heat transfer, larger electric fields, large magnetic fields, etc. I present a multifunctional double gyroid capacitor that is designed for three functions (1) load bearing, (2) energy storage, and (3) self-sensing deformations. To characterize the load bearing capabilities, I studied the mechanical properties of four elastomeric gyroid unit cells. My analysis includes finite element models verified with 3D printed samples tested under compression and tension. The second multifunctional system that I present is a semi active damper with an integrated redox flow battery. The triply periodic minimal surface used in this device is designed for passive damping and flowing electrolyte to the electrode of the battery. The electrolyte of the battery has a double purpose of (1) flowing ions through the electrodes to convert chemical energy into electrical energy and (2) acting as the hydraulic fluid for damping. Lastly, I present my work on two approaches to fabricate patient specific coronary artery models. The first approach is synthesizing new hydrogel materials for 3D printing that will enable us to print materials soft enough to match the mechanical properties of coronary arteries. The second approach is leveraging metamaterials as an alternative to multimaterial printing. As DLP printers are limited in their ability to produce resilient multi-material parts, the utility of the lattices affects similar outcomes as multi-materials while using only one chemistry in addition to producing nonlinear stress-strain curves not readily achievable with material alone.

Name thesis:degree_name

Ph. D., Mechanical Engineering

Level thesis:degree_level

Doctor of Philosophy

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

Cornell University

Year dc:date.issued

2023

Author dc:creator

• Baker, Emilie

Committee members dc:contributor.committeemember

• Lal, Amit
• Silberstein, Meredith

• damper
• double gyroid capacitor
• embodied energy
• metamaterials
• redox flow battery
• triply periodic minimal surfaces

Language dc:language.iso

en

DOI

https://doi.org/10.7298/vd3b-rb46

Dc Identifier Other

ProQuest Submission ID: 13870
ProQuest Publication ID: 30574777

OAI identifier oai:identifier

oai:ecommons.cornell.edu:1813/114572