Plasmas for additive manufacturingmipse.umich.edu/files/oltp_2020-12-08_Sankaran.pdf · 2020. 12. 8. · 2. additive manufacturing (AM) – a process of joining materials to make

Plasmas for additive manufacturingOLTP SeminarSee Y. Sui et al., Plasma Proc. Polym. 17, e20000009 (2020).

R. Mohan SankaranDonald Biggar Willett Professor in EngineeringDepartment of Nuclear, Plasma, and Radiological Engineering

Email: [email protected]: https://speclab.npre.Illinois.edu

2

additive manufacturing (AM) – a process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing technologies.

ASTM F2792-12a: Standard Terminology for Additive Manufacturing Technologies, 2013.

Subtractive vs. additive approaches to materials manufacturing

3

Subtractive:

Additive:

Material wasteage, relatively fast and easy, ideal for large parts

Slow and complex, enables intricate geometries, small parts

Examples of additive manufacturing

4

1980 1990 2000 2010

Williams, VTech

Greer, Caltech

Selective laser sintering: Fraunhofer Institute, 1995

Forced deposition modeling: Crump, 1988

Binder jetting: Sachs, MIT, 1993

Stereolithography: Kodama, Nagoya MIRI, 1980; Hull, 3D Systems Corp., 1984

FDM patent ends, 2009

Cold spray: 2000sSpee3D

Thin film printing approaches

5

Screen printing(Doctor’s blade)

(Gravure printing)

Inkjet printing(Aerosol jet printing)

Limited to a few metals (Ag, Cu, …)

Opportunities for plasmas in additive manufacturing

6

•Low-temperature•Gas-phase•Non-equilibrium chemistry•Conformal

PLASMA

NEW MATERIALS•Metals•Semiconductors

PROCESSING•Direct deposition•Hard/Soft SURFACE TREATMENT

•Hydrophilic/phobic•Functionalization

REMOVAL•Etching/sputtering•Corrections

MULTIPHASE•Liquids•Aerosols

Opportunities for plasmas in additive manufacturing

7

•Low-temperature•Gas-phase•Non-equilibrium chemistry•Conformal

PLASMA

NEW MATERIALS•Metals•Semiconductors

PROCESSING•Direct deposition•Hard/Soft SURFACE TREATMENT

•Hydrophilic/phobic•Functionalization

REMOVAL•Etching/sputtering•Corrections

MULTIPHASE•Liquids•Aerosols

Potential strategies for plasma synthesis of printed structures

8

DIRECT WRITE


9

DIRECT WRITE

( )


10

DIRECT WRITE

POST-PRINT

( )

11

I. Direct writea. Nanoparticle depositionb. Reduction of dispersed metal salts

II. Post-printa. Sinteringb. Conversionc. Beyond metals

12



Synthesis of nanoparticles from liquid aerosol droplets

13

Au3+ Au

e-

P. Maguire et al., Nano Lett. 17, 1336 (2017).

Plasma Droplet

Plasma jet printing of metals from liquid aerosols

14 A. Dey et al., J. Vac. Sci. Technol. B 37, 031203 (2019).

Space Foundry Inc., Moffett Field, CA

15



Localized conversion of thin films of metal precursor and polymer

16

Aqueous solution of polymer and metal salt

Localized conversion of thin films of metal precursor and polymer

17

Aqueous solution of polymer and metal salt Doctor’s blade coating (spin coating, etc.)

Electrical characterization of AgNO3/PVA films

18

-4 -2 0 2 4-6

-4

-2

0

2

4

6

As-deposited film Plasma exposed

Cur

rent

(x10

-8 A

)

Voltage (V)

R=82 MΩρ=122 kΩ-cm*

Large resistance may be due to poor morphology (not completely percolating).

At higher Ag precursor loading, solutions are unstable.

2-point probe measurement

3 μm

ACS Appl. Mater. Inter. 6, 2099 (2014).

*Ag: 1.59 μΩ-cm

Polyacrylic acid as a polymer matrix

19

Ag+

PAAr:Ag+ = 1:0.32


Polyacrylic acid as a polymer matrix

20

Ag+1:0.32

1:0.64

Percolating network

500 nm

500 nm


Cross-sectional EDS of microplasma-reduced Ag-PAA films

21

20 µm

20 µm

20 µm

20 µm

Unreduced sample Reduced region


Proposed electric migration mechanism for surface-rich Ag layer

22

𝐸𝐸

Cathode

Anode

Ag-PAA film

Microplasma jet

ACS Appl. Mater. Inter. 6, 2099 (2014).Plasma Chem. Plasma Proc. 36, 295 (2016).

Electrical conductivity depends on initial film thickness

23

Film acts as a “reservoir” for the reduction and formation of Ag at the surface.

-1.0 -0.8 -0.6 -0.4 -0.2 0.0 0.2 0.4 0.6 0.8 1.0

-10

-5

0

5

10

10 µm 20 µm 40 µm 80 µm

Cur

rent

(µA)

Voltage (V)10 20 30 40 50 60 70 80 90

101

102

103

Res

istiv

ity (Ω

-cm

)Film thickness (µm)

1:0.32 PAAr:Ag

*Ag: 1.59 μΩ-cm*ITO: 0.1 Ω-cm*Ag NP inks: 5 μΩ-cm-10 Ω-cm


Integration of reduced Ag-PAA films with elastomeric PDMS substrates

24 ACS Macro. Lett. 6, 194 (2017).

Ag-PAA PDMSMix & centrifuge

Blade casting

Microplasma reduction (AC)

AgNO3PAA

Conductivity as a function of strain in Ag-PAA on PDMS films

25

0 5 10 15 20 25 30 35 40 450

20

40

60

80

100

33%

27%

R/R

0

Strain (%)

AuPDMS

0%

Prestrained

15%

27%

33%

ACS Macro. Lett. 6, 194 (2017).

SEM analysis of microstructure during straining

26

17% 35%

PrestrainedSt

rain

ing

dire

ctio

n

As-deposited

ACS Macro. Lett. 6, 194 (2017).

27



Need for sintering of printed nanoparticle inks

28

> 200 oC

O. Kravchuk et al., NANO 2017, 317 (2018).

< 150 oC

Plasma sintering

29

S. Wunscher et al., J. Mater. Chem. 22, 24569 (2012).

S. Ma et al., Appl. Surf. Sci. 293, 207 (2014).

30



Plasma conversion: Metal-organic decomposition (MOD) inks

31 Y. Farraj et al., ACS Appl. Mater. Inter. 9, 8766 (2017).

< 60 oC

Plasma conversion: Metal-organic decomposition (MOD) inks

32 Y. Farraj et al., ACS Appl. Mater. Inter. 9, 8766 (2017).

< 60 oC

Plasma conversion: Metal salts dispersed in aqueous solutions

33 J. Vac. Sci. Technol. A 36, 051302 (2018).

AgNO3 Ag


34 Adv. Mater. Technol. 4, 1900119 (2019).

< 77 oC < 138 oC



Tg ~ 75 oC 80 oC 100 oC(melting)

Characterization of printed and plasma converted metals


Cu:

Au:

Potential mechanism for plasma conversion of printed metal salt films


Sn2+

Sn0

Sn2+

Sn0

38



Plasma conversion (reduction) of graphene oxide


Characterization of plasma-converted rGO


Atmospheric-pressure dielectric barrier (DBD) reactor with cold wall substrate heater

41

6 mm

5 mm

4 mm

3 mm

Electrode gap

Plasma conversion of spin-coated ammonia borane to h-BN thin films (Ar only)

42

1100 1200 1300 1400 1500 1600

1000 °C

800 °C

650 °C

Inte

nsity

(A.U

.)

Raman shift (cm-1)

Micro Raman spectroscopy:


500 1000 1500 2000 2500 3000 3500

Bulk h-BN reference

Inte

nsity

(A.U

.)

Raman shift (cm-1)

Ammonia borane

1366 cm-1

Plasma conversion of spin-coated ammonia borane to h-BN thin films (Ar only)

43

1100 1200 1300 1400 1500 1600

1000 °C

800 °C+ plasma

800 °C

650 °C

650 °C + plasma

Inte

nsity

(A.U

.)

Raman shift (cm-1)500 1000 1500 2000 2500 3000 3500

Bulk h-BN reference

Inte

nsity

(A.U

.)

Raman shift (cm-1)

Ammonia borane

1366 cm-1



Plasma conversion of spin-coated ammonia borane to h-BN thin films (Ar + H2)

44

1100 1200 1300 1400 1500 1600

800 oC+ plasma

800 oC

650 oC

650 oC+ plasma

500 oC + plasma

500 oC

Inte

nsity

(A.U

.)

Raman shift (cm-1)



Assessment of film crystallinity by Raman analysis

45

400 600 800 1000 12000

10

20

30

40

50

60

70

(a)(b)

(c)

(f)

(d) Metal CVD

Si CVD

Plasma

FWH

M (c

m-1

)

Temperature (oC)

Thermal

(e)

𝐿𝐿𝑎𝑎 = 1417Γ1/2

− 8.7*

FWHM (Γ1/2) is inversely rated to crystalline domain size (La):

(a)S. Behura et al., J. Am. Chem. Soc. 137, 13060 (2015).(b)S. Behura et al., ACS Nano 11, 4985 (2017).(c)R. Y. Tay et al., Appl. Phys. Lett. 106, 101901 (2015).(d)L. Song et al., Nano Lett. 10, 3209 (2010).(e)J-H. Park et al., ACS Nano 8, 8520 (2014).(f) S. M. Kim et al., Nat. Comm. 6, 8862 (2015).

*R. Nemanich et al., Phys. Rev. B 23, 6348 (1981).


Proposed mechanism for plasma-enhanced chemical film conversion (PECFC)

46

S. Frueh et al., Inorg. Chem. 50, 783 (2011).

S. Sriraman et al., Nature 418, 62 (2002).J. C. Angus et al., Science 241, 913 (1988).

Proposed mechanism for plasma-enhanced chemical film conversion (PECFC)

47

S. Frueh et al., Inorg. Chem. 50, 783 (2011).

400 500 600 700 800

Ar/H2 background (80:20)Hα

Inte

nsity

(A.U

.)

Wavelength (nm)

Ar background


Demonstration of h-BN films as gate dielectric in 2D device

48

-30 -20 -10 0 10 20 300.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

without h-BN

Vds = 100 mV

I ds

(µA )

Vg (V)

x 10

with h-BN

Without h-BN With h-BN0

5

10

15

20

25

Mob

ility

(cm

2 /Vs)

-0.10 -0.05 0.00 0.05 0.10

-1.0

-0.5

0.0

0.5

1.0 +100 V +90 V +80 V +70 V +60 V +50 V +40 V +30 V +20 V +10 V 0 V

I ds

(µA )

Vds (V)

Gate voltage


Extending PECFC to other layered materials: MoS2 from (NH4)2

2+MoS42- (ATM)

49 J. Vac. Sci. Technol. 38, 063006 (2020).

340 370 400 430In

tens

ity (A

.U.)

Raman shift (cm-1)

as-converted

500 oC

800 oC

1000 oC

E12g

A1g

Spin-coated precursor film Plasma-enhanced conversion step High temperature annealing

Plasma induces nucleation, growth, and crystallization

50

340 370 400 430

Inte

nsity

(A.U

.)

Raman shift (cm-1)

Thermally-treated (500 oC)

Thermally-treated + annealed

E12g

A1g

J. Vac. Sci. Technol. 38, 063006 (2020).


Plasma induces nucleation, growth, and crystallization

51

340 370 400 430

Inte

nsity

(A.U

.)

Raman shift (cm-1)

Thermally-treated (500 oC)

Thermally-treated + annealed

Plasma-triggered + annealed E1

2g

A1g

J. Vac. Sci. Technol. 38, 063006 (2020).


Plasma-triggered film Annealed film

Precursor film

Ar/H2, 500 oC

Ar, 25 oC Ar, 1000 oC

Ar, 1000 oC

Thermally treated

Strain generation in MoS2 films

52

360 370 380 390 400 410 420 430 440

Plasma converted

Inte

nsity

(A.U

.)

Raman shift (cm-1)

A1g

E12g

Plasma converted+

annealed

ACS Appl. Energy Mater. 2, 5163 (2019).

236 234 232 230 228 226 224

S 2s

Mo 3d5/2

Nor

mal

ized

inte

nsity

(A.U

.)

Binding energy (eV)

PECFC (500 oC) Post thermal (1000 oC)

Mo 3d3/2

166 164 162 160

S 2p3/2

Nor

mal

ized

inte

nsity

(A.U

.)Binding energy (eV)

PECFC (500 oC) Post thermal (1000 oC)

S 2p1/2

X-ray photoelectron spectroscopy:

S:Mo ratio is constant!


Types of defects in MoS2

53

AFM characterization of plasma converted MoS2 films: evidence for rippling

54

PECFC (500 oC) Annealed (1000 oC)

RMS roughness: 1.7 nm RMS roughness: 0.5 nm


Plasma converted MoS2 as catalyst for hydrogen evolution reaction (HER)

55

-0.7 -0.6 -0.5 -0.4 -0.3 -0.2-20

-15

-10

-5

0

Bare Cu

Post thermal(1000 oC)C

urre

nt d

ensi

ty (m

A/cm

2 )

Potential (V vs. SHE)

PECFC(500 oC)

Polarization curves in 0.5 M H2SO4:

0 40 80 120 160 2000.00

0.05

0.10

0.15

0.20

0.25 As-grown High T

Cur

rent

den

sity

at 0

V v

s. S

HE

(mA/

cm2 )

Scan rate (mV/s)

Edges

Double layer capacitance:


Plasma converted MoS2 as catalyst for hydrogen evolution reaction (HER)

56

-0.7 -0.6 -0.5 -0.4 -0.3 -0.2-20

-15

-10

-5

0

Bare Cu

Post thermal(1000 oC)C

urre

nt d

ensi

ty (m

A/cm

2 )

Potential (V vs. SHE)

PECFC(500 oC)

Polarization curves in 0.5 M H2SO4:

0 40 80 120 160 2000.00

0.05

0.10

0.15

0.20

0.25 As-grown High T

Cur

rent

den

sity

at 0

V v

s. S

HE

(mA/

cm2 )

Scan rate (mV/s)

Edges

Double layer capacitance:

Sample Double layer capacitance Tafel slope Current at -0.5

V vs. SHE Site density TOF

(mF/cm2) (mV/dec) (mA) (1015/cm2) (H2 s-1 /surface site)

PECFC (500 oC) 1.25 91 18.7 24.3 2.4

Post thermal (1000 oC) 0.63 127 1.6 12.1 0.4


Unique features of plasmas for AM: Ability to chemically convert, not just heat/sinter Gas-phase species for nucleation/growth and crystallization Charged species for low-temperature dissociation, electric migration, and defect

generation

Challenges to overcome for AM: Lower processing temperatures even further for materials beyond metals Decrease resolution for direct write Integrate with existing tools for 3D fabrication

Take home messages

57

Acknowledgements

58

Funding:

Collaborators

CWRU

Chemical and Biomolecular Engineering:

• Craig Virnelson

• Prof. C.C. Liu

• Prof. Rohan Akolkar

Materials Science and Engineering:

• Dr. Amir Avishai

• Dr. Jonathan Cowen

• Dr. Danqi Wang

Electrical Engineering and Computer Science:

• Dr. Yongkun Sui (University of Colorado Boulder)

• Prof. Christian Zorman

Alumni

• Carolyn Richmonds (Ph.D. candidate, Northwestern

University)

• Dr. Seung Whan Lee (NAFRI)

• Megan Witzke (Exxon Mobil, New Jersey)

• Brittany Bishop (Ph.D. candidate, University of

Washington)

• Dr. Souvik Ghosh (Intel)

• Evan Ostrowski (Ph.D. candidate, Princeton University)

• Dr. Tianqi Liu (Chinese Academy of Science)

• Ryan Hawtof (Ph.D. candidate, MIT)

Current group members

• Souvik Bhattacharya (Ph.D. candidate)

Documents

Plasmas for additive manufacturingmipse.umich.edu/files/oltp_2020-12-08_Sankaran.pdf · 2020. 12. 8. · 2. additive manufacturing (AM) – a process of joining materials to make