SungWoo Namhttp://nam.mechse.illinois.edu

Mechanical Science and EngineeringMaterials Science and Engineering

University of Illinois at Urbana-Champaign

Mechanically-driven Nano-manufacturing of Atomically-thin Origami

and Kirigami Structures

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Atomically-thin, 2D Materials

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Nature Photonics 8, 899 (2014).

Topography vs. Plasmons

• Crumpling graphene enables the enhanced plasmonic resonance in the near/mid infrared wavelengths (1-10 µm) which is difficult to achieve with the lithographically patterned graphene nanostructures (e.g. graphene ribbons, disks, rings, and stacks).

• Stretching/releasing of crumpled graphene enables new possibilities of reconfigurable graphene plasmonics (meta-materials).

Kang Kang & Nam, Light 7, 17 (2018).

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Kang

Topography vs. Plasmons

Kang & Nam, Light 7, 17 (2018).

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Kang

Topography vs. Plasmons

Kang & Nam, Light 7, 17 (2018).

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Kang & Nam, Light 7, 17 (2018).

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Topography vs. Plasmons

Kang

Topography vs. Plasmons

Our analytical model accurately describes the surface plasmon resonance of crumpled graphene with small to large h/λc (0.2−2).

0 200 400 600 800 10000

5

10

15

20

25

h/c = 0.5

h/c = 1.0

h/c = 1.5

h/c = 2.0

re

s (

μm

)

c (nm)

Kang Kang & Nam, Light 7, 17 (2018).

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Mechanically-driven Nano-manufacturing of Ultrathin Kirigami Structures

Experiment vs. Simulation

Parametric Optimization

Tool Wireframe

nanoMFG node thrust:VI Nanoscale Self Assembly

PIs and Students: Aluru & Nam (PIs); De & Yong (students)

Objectives: Develop a simulation tool capable of nano-mechanics driven manufacturing of ultrathin kirigami structures for meta materials.

(1) Develop continuum mechanics model for several deformation modes(2) Experimental verification of final structures

Significance:Use mechanical self-assembly to create multifunctional structures and morphologies in nanoscale

http://nanomfgnode.illinois.edu/

8 um PIεfrac ~ 266%

4 um PI Stress (MPa)

εfrac ~ 197%

Stress (MPa)

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Inspirations for Kirigami Architecture

Kirigami Paper/Nanocomposite Graphene Kirigami

• In traditional kirigami, cut or notches are introduced into paper sheets to attain adesirable topology on folding.

• 2D kirigami surface architectures can be transformed into strain-responsive 3Darchitectures in the vicinity of patterned regions owing to mechanical bi-stability.

Kotov et al., Nat. Mat, 14 (2015)McEuen et al., Nature., 524 (2015)

http://nanomfgnode.illinois.edu/

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Predictive Deformation Modes

Z-displacement (mm)

1

0

Stress (MPa)

-1

200

150

100

0

50

1 2 3 4 5 6 7 8FixedBoundary

FixedBoundary

FixedBoundary

FixedBoundary

http://nanomfgnode.illinois.edu/ Unpublished results

nanoHUB Tool Interface (1)

12http://nanomfgnode.illinois.edu/

https://nanohub.org/tools/gamian