2026-09-19T07:56:11Zhttps://ecommons.cornell.edu/server/oai/requestoai:ecommons.cornell.edu:1813/1109002026-05-15T19:43:56Zcom_1813_35col_1813_47
O'Neill, Maura Rose
Shepherd, Robert F.
Lal, Amit
Petersen, Kirstin Hagelskjaer
2022-01-24T18:08:15Z
2023-01-05T07:00:26Z
2021-12
ProQuest Submission ID: 12849
ProQuest Publication ID: 28861793
https://hdl.handle.net/1813/110900
https://doi.org/10.7298/kct9-g734
15312756
145 pages
Supplemental file(s) description: Supplemental Video for Chapter 2.
Elastomeric, dielectric architectures exhibit versatile functionality. Depending on their material properties and geometric structure, dielectric architectures can facilitate the transformation of an object’s shape, sense local deformation, or even alter the transmission of electromagnetic waves in the surrounding envi- ronment. This work develops and characterizes soft material systems and fab- rication frameworks for multi-dimensional mobility and topological morphing. A comprehensive material system is introduced for the additive manufactur- ing of soft, electrohydraulic tentacle actuators. A photo-curable, elastomeric silicone-urethane with strong dielectric properties (εr ≈ 8.8 at 1 kHz) serves as the encapsulating material for ionically-conductive hydrogel and silver paint electrodes that displace a vegetable-based liquid dielectric under an applied electric field. A fully-encapsulated and 3D printed electrohydraulic tentacle actuator—containing a three-dimensional array of 30 actuators—demonstrates the use of this material system in a synthetic hydrostat with multi-dimensional motion. This technology is extended to toplogical morphing with dual-phase capacitive actuators to design conformable reflectarray antennas with beam- steering capabilities. A silicone-urethane membrane with carbon and copper electrodes encapsulates a dual gas-liquid working fluid (N2 gas and Envirotemp FR3 liquid, εr = 3.2) to create a lightweight and rapid reconfiguration mech-anism. A pair of the capacitive actuators can exhibit a free displacement of ∆d ≈ 1.4 mm with only 0.34 g of working fluid (46wt% N2 gas). This work also introduces a numerical and experimental study of dielec- tric elastomer architectures that can serve as flexible metamaterials for adaptive electronics. The unit cell design and porosity of two dielectric elastomeric archi- tectures provides a tuning mechanism for the onset of a mechanical instability in the structure; a shift in effective permittivity is observed due to the increase in matrix volume and the rearrangement of the electric field distribution in the cells. Additive fabrication allows rapid customization of the unit cell geome- try and scale for tuning the matrices’ electromechanical response. We observed effective permittivity shifts ∆ε2 > 0.7 under compressive strains γ < 0.35. With the ability to tune their effective mechanical behavior, the architected elastomers are more flexible than their bulk polyurethane counterpart for flexible electronic applications. A demonstration of the 3D printed architectures as soft, flexible substrates for a microstrip patch antenna show tunable shifts in resonance fre- quency
∆ fr
> 110 MHz under compression.
en
DESIGN, MANUFACTURING, AND CHARACTERIZATION OF SOFT, CAPACITIVE ACTUATORS AND ARCHITECTED DIELECTRIC ELASTOMERS
dissertation or thesis
https://newcatalog.library.cornell.edu/catalog/15312756
application/pdf
video/mpeg4
Mechanical Engineering
Cornell University
Doctor of Philosophy
Ph. D., Mechanical Engineering
https://hdl.handle.net/1813/59810.2
Publication
Cornell Theses and Dissertations
O'Neill, Maura Rose
5893a6ea-7af3-41d7-abc6-04bcd26ab5df
open.access
open.access
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<Abstract>Elastomeric, dielectric architectures exhibit versatile functionality. Depending on their material properties and geometric structure, dielectric architectures can facilitate the transformation of an object’s shape, sense local deformation, or even alter the transmission of electromagnetic waves in the surrounding envi- ronment. This work develops and characterizes soft material systems and fab- rication frameworks for multi-dimensional mobility and topological morphing. A comprehensive material system is introduced for the additive manufactur- ing of soft, electrohydraulic tentacle actuators. A photo-curable, elastomeric silicone-urethane with strong dielectric properties (εr ≈ 8.8 at 1 kHz) serves as the encapsulating material for ionically-conductive hydrogel and silver paint electrodes that displace a vegetable-based liquid dielectric under an applied electric field. A fully-encapsulated and 3D printed electrohydraulic tentacle actuator—containing a three-dimensional array of 30 actuators—demonstrates the use of this material system in a synthetic hydrostat with multi-dimensional motion. This technology is extended to toplogical morphing with dual-phase capacitive actuators to design conformable reflectarray antennas with beam- steering capabilities. A silicone-urethane membrane with carbon and copper electrodes encapsulates a dual gas-liquid working fluid (N2 gas and Envirotemp FR3 liquid, εr = 3.2) to create a lightweight and rapid reconfiguration mech-anism. A pair of the capacitive actuators can exhibit a free displacement of ∆d ≈ 1.4 mm with only 0.34 g of working fluid (46wt% N2 gas). This work also introduces a numerical and experimental study of dielec- tric elastomer architectures that can serve as flexible metamaterials for adaptive electronics. The unit cell design and porosity of two dielectric elastomeric archi- tectures provides a tuning mechanism for the onset of a mechanical instability in the structure; a shift in effective permittivity is observed due to the increase in matrix volume and the rearrangement of the electric field distribution in the cells. Additive fabrication allows rapid customization of the unit cell geome- try and scale for tuning the matrices’ electromechanical response. We observed effective permittivity shifts ∆ε2 > 0.7 under compressive strains γ < 0.35. With the ability to tune their effective mechanical behavior, the architected elastomers are more flexible than their bulk polyurethane counterpart for flexible electronic applications. A demonstration of the 3D printed architectures as soft, flexible substrates for a microstrip patch antenna show tunable shifts in resonance fre- quency</Abstract>
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