IDML Introduction

Functional Micro/Macro Additive Manufacturing

Jae-Won Choi, Ph.D., Assistant ProfessorDirector, Innovative Design and Manufacturing Laboratory,

Mechanical Engineering, The University of Akron

Feel free to contact if you have any questionsE-mail: [email protected]

Functional Micro/Macro Additive Manufacturing J.W. ChoiJ.W. Choi

ContentsContents

IntroductionIntroduction

Projects Review

Applications - 3D Functional Microstructures

Future Work

Innovative Design and Manufacturing Lab 2


IntroductionIntroduction

Additi M f t i- Additive Manufacturing



Additive Manufacturing (AM)Additive Manufacturing (AM) What is AM ?

Definition

• Process of joining materials to make objects from 3D model data, as opposed to subtractive manufacturing (lathes, mills, etc.)

• AM is a standard terminology defined by ASTMgy y

• Rapid Prototyping (RP), Solid Freeform Fabrication (SFF), L d M f i (LM) Addi i F b i iSynonyms Layered Manufacturing (LM), Additive Fabrication, etc.

Coverage

• Pre-production (Rapid Prototyping) to Rapid Manufacturing and Tooling.



Representative AM ProcessRepresentative AM Process Stereolithography

Apparatus (SLA)• Working principle

Curing photocrosslinkable liquid material using a laser

• Examples



Representative AM ProcessRepresentative AM Process Fused Deposition

Modeling (FDM)• Working Principle

Depositing a molten material using a filament and heated nozzles

• Examples



Representative AM ProcessRepresentative AM Process Selective Laser

Sintering (SLS)• Working Principle

Sintering a powder material using a CO2laser

• Examples



Representative AM ProcessRepresentative AM Process Electron Beam

Melting (EBM)• Working Principle

selectively melting Ti-6Al-4V powder using an electron beam

• Examples



Additive ManufacturingAdditive Manufacturing Various processes

Additive manufacturing

processes

Powder materials

Sintering Printing or joining

Liquid materials

Extrusion process Liquid

polymerizati

Solid materials

Bonding of sheets with

Bonding of sheets withg

process

Selective Laser

Sintering (SLS)

joining process

3D Printing (3DP)

p(molten

material)

Fused Deposition Modeling

(FDM)

polymerization process

Photo-masking

processesLaser

processesDeposition

process

sheets with adhesive

Laminated Object

Manufacturing (LOM)

sheets with light

Foil polymerizati

on(SLS) (FDM) p

Solid Ground Curing (SGC)

Dynamic-mask

ProjectionStereolithogr

aphy (SL)Multi-Jet Modeling

(MJM)

(LOM)



Projects Review

- Macro Additive

Manufacturing



Micro-channel Fabrication in SLAMicro channel Fabrication in SLA

Using micro-wires in SLA

Build open micro-channel

Place micro-wire in channel

Complete build (embed wire)

Remove wire

57 2 i 83 5 µm wire


Choi, J.W. *, Quintana, R., Wicker, R., Rapid Prototyping Journal, 17 (5), 2011.

31.6 µm wire 57.2 µm wire 83.5 µm wire


Advanced AM IAdvanced AM I Multiple Material Stereolithography (MMSL)

Build using material 1Raise the platform

Manual Cleaning and drying the platform with a part

Rotate material vat 1 under build platform Finished multiple

material part

Continue the process to build multiple material

functional devices Rotate material vat 2 under build platform

Build using material 2


Kim, H.C., Choi, J.W., MacDonald, E., Wicker, R.B. International Journal of Advanced Manufacturing Technology, 46: 1161-1170, 2010.

Kim, H.C., Choi, J.W., Wicker, R.B., Rapid Prototyping Journal, 16: 232-240, 2010.


Advanced AM IAdvanced AM I Multiple Material Stereolithography (MMSL)


Choi, J.W., Kim, H.C., Wicker, R., “Multi-material stereolithography,” Journal of Materials Processing Technology, 211: 318-328, 2011..


Advanced AM IAdvanced AM I Multiple Material Stereolithography (MMSL)1 2

Building the bottom using the material 1 Building the half hollow structure using theBuilding the bottom using the material 1(diluted ProtoTherm 12120 (Red))

g gmaterial 2 (diluted WaterShed 11120 (Clear))

3 4


Building the other half hollow structureusing the material 3 (diluted 14120 White)

Building the staircase, spirals, and topusing the material 1

Applications (NGCs, medical models)


Advanced AM IIAdvanced AM II Flexible Fused Deposition Modeling (FFDM)


Choi, J.W., Medina, F., Kim, C., Espalin, D., Rodriguez, D., Stucker, B., Wicker, R. “Development of a Mobile Fused Deposition Modeling System with Enhanced Manufacturing Flexibility,” Journal of Materials Processing Technology, 211: 424-432, 2011


Advanced AM IIAdvanced AM II Flexible Fused Deposition Modeling (FFDM)



Projects ReviewProjects Review

- Micro Additive

Manufacturing:Microstereolithography



Micro AM - MicrostereolithographyMicro AM - Microstereolithography What is Microstereolithography (µSL)

• Process of layer-by-layer joining materials to make micro-objects

• Evolved from conventional stereolithography (SL)• Evolved from conventional stereolithography (SL)• Typically the x-y resolution of a few microns and z

resolution of a few tens of microns• Types

Scanning µSLSi il t ti l SL– Similar to conventional SL

– Using a focused laser (beam spot size ≤ 10 µm)Projection µSL


– Using a physical or dynamic (or digital) mask (pattern size ≤ 5 µm)


µSL - History1960IC Technology

µSL - History

1970

1980

MEMS

1990

19861988

1993

LIGA, Berker et al.

SLA, Hull

Ikuta and Kirowatari 1993

1996

199

Two-photon, Maruo et al.Mask-based MSL,Nagomoto et al.

LCD MSL B h l

Tagaki et al.

2000

1997

2001

2003

LCD-MSL, Bertsch et al.

DMD-MSL, Bertsch et al.

Commercial Microsintering,


MSL : MicrostereolithographyLCD : Liquid crystal displayDMD : Digital micromirror device

2003

2004

g,Micromac

Acculas, Commercial MSL, D-Mac


DMD-based projection µSLDMD-based projection µSL

Choi J W Ha Y M Lee S H Choi K H Journal of Mechanical Science and Technology 20: 2094 2104 2006


Choi, J.W., Wicker, R.B., Cho, S.H., Ha, C.S., Lee, S.H., Rapid Prototyping Journal, 15: 59-70, 2009.

Choi, J.W., Ha, Y.M., Lee, S.H., Choi, K.H., Journal of Mechanical Science and Technology, 20: 2094-2104, 2006.


DMD-based projection µSL Configuration

DMD-based projection µSL

• Light emission subsystemMercury lamp with the output of 200 W Filtered at the wavelength of 365 nmFiltered at the wavelength of 365 nm


EXFO OmniCure S2000TM model Lamp output




• Dynamic pattern generation subsystemTexas InstrumentTexas Instrument1024 by 768 micro-mirror arrayMirror size of 13.68 µm

DMD

±12° tilting angle to selectively reflect a light bundle

-12 degrees tilt( ff t t ) Flat state (not energized)

Off state (dummy light)(-12 degrees tilt)

24

+12 degrees tilt

(off state)

Flat stateOn state for image-forming

(+12 degrees tilt)

Incident light

Flat state (not energized)

24

24

24


DMD Discovery 1100TMController Board

+12 degrees tilt(on state)

Incident light

DMD operation




• Image focusing subsystemObjective lenses with different

numerical apertures (N.A.)numerical apertures (N.A.)

• Build subsystemHigh-resolution z stage (100

)

NA: 0.13 NA: 0.3 NA: 0.45

nm)Custom made platform



DMD-based projection µSL Deep-dip process


• Settling time is required• Low viscosity resin is required

Unstable resinsurface

Refreshed resin surface

Projection lens

FocusedlightFabricated

layer

Platform

Vat

(a) (b) (d)(c)Resin(a) (b) (d)(c)

(a) Step 1 : Irradiation for given time

(b) Step 2 : Fast moving downward to cover fabricated layer

(c) Step 3 : Slow moving upward to desired position

Resin


(c) Step 3 : Slow moving upward to desired position

(d) Step 4 : Waiting until resin surface becomes flat


DMD-based projection µSL Material issues


• Photocrosslinkable and low viscosity liquid materials• Commercial resins

SI40 id d b 3D S t (R k Hill SC)SI40 provided by 3D Systems (Rock Hills, SC)WaterShed 11120, ProtoTherm 12120, and Somos® 14120 White

provided by DSM Somos® (New Castle, DE)

• Most of commercial resins are too viscousacrylate- or diacrylate-based monomers as diluentsA viscosity of less than ~200 cP is recommendedA viscosity of less than 200 cP is recommendedpropoxylated (2) neopentyl glycol diacrylate1,6-hexanediol diacrylate (HDDA) i b l l t (IBXA IBOA)


isobornyl acrylate (IBXA or IBOA)


DMD-based projection µSL Material issues


• Monomers, oligomers, and polymers availableCrosslinkable sites such as a carbon doubleCrosslinkable sites such as a carbon double

bondPhotoinitiator (PI) is required

Depends on the wavelength of a chosen light– Depends on the wavelength of a chosen light

• Overcure and cure depth controlCuring characterization for photocrosslinkable

materials is defined by critical energy (Ec) and light penetration depth (Dp)

For cure depth control, a light absorber is


required


Fabrication examplesFabrication examples

Dime



Fabrication examplesFabrication examples

30 µm

~30 µm

~30 µm

~50 µm

10 µm

~130 µm

~10 µm



Advanced µSL I Large-area

Advanced µSL I

DMD

Optical fiberCollimating lens set

Focusing unitReflecting mirror

fabrication• Additional high

i i t Lamp

LightGate

precision x-y stage under the system

Z StageTube lens

X-Y StageObjective lens

Resin Vat


Ha, Y.M., Choi, J.W., Lee, S.H., Journal of Mechanical Science and Technology, 22: 514~521, 2008.


Advanced µSL I Large-area fabrication

Advanced µSL I




Advanced µSL I




Advanced µSL I




Advanced µSL I

3D model fabricated teeth



Advanced µSL II Multi-material fabrication

Advanced µSL II

• Using additional syringe pump and custom-made small vat• Manual washing process


Choi, J.W. *, MacDonald, E., Wicker, R.B., International Journal of Advanced Manufacturing Technology, 49: 543-551, 2010.



Advanced µSL II

• Single material fabrication in the developed system




Advanced µSL II



µSL Applications

- 3D Functional

Microstructures



µSL Applications I Fluidics Biomedical

3D micro-vanes within a

µSL Applications I – Fluidics, Biomedical

sleeve

sleeve in cataract surgery• Phacoemulsification

Removing the crystallineultrasound irrigation

– maintaining a constant pressurephacoemulsifier

Irrigation tip

– dissipating heat– maintaining an endothelial cell survival– Impinging flow from the irrigation

solution on the corneal endothelial cells in the inner eye damages these cells during the procedure

It i i d t d th fl

artificial lens


It is required to reduce the flow velocity during the procedure

Source: http://www.eyesurgeryeducation.com


µSL Applications I Fluidics Biomedical

3D micro-vanes within a sleeve in cataract surgery

µSL Applications I – Fluidics, Biomedical


Choi, J.W. *, Yamashita, M., Sakakibara, J., Kaji, Y., Oshika, T., Wicker, R. Biomedical Microdevices, 12: 875-886, 2010.


µSL Applications II Electrical Mechanical

3D micro-patterns for conductive wires

µSL Applications II – Electrical, Mechanical



µSL Applications III Tissue Engineering

Tissue engineering scaffolds

µSL Applications III – Tissue Engineering

• Artificial structure or template to support implanted or seeded cells to be a three-dimensional tissue scaffolds requirements: degradation rate, porosity, pore size, shape,

di t ib ti d h i l tidistribution, and mechanical propertiesmaterials requirements

– Biodegradability: degradable into nontoxic products, leaving the desired living tissuetissue

– Biocompatibility: not to provoke any unwanted tissue response to the implants and to possess the right surface chemistry to promote cell attachment & functionM f t bilit– Manufacturability

optimal scaffold pore size and geometry vary according to cell types 3D design and fabrication are necessarily needed




Tissue engineering scaffolds


• Biodegradable/biocompatible/photocrosslinkable• Poly(propylene fumarate) (PPF) is a good material

O i i ll d l d f b tiOriginally developed for bone regenerationSynthesized using propylene glycol and diethyl fumaratePPF can be diluted with diethyl fumarate

OOEt HO HO

OO

EtOOEt

O

HOOH

Diethyl fumarate (DEF) Propylene glycol (PG)

HOO

O

OOHn

PPF




Tissue engineering scaffolds using PPF/DEF



Choi, J.W., Choi, K.H., Chung, I., Ha, C.S., Lee, S.H, Wicker, R.B., Journal of Materials Processing Technology, 29: 5494-5503, 2009


µSL Applications IV Microneedles for transdermal drug delivery

µSL Applications IV

• Stratum corneum is the main barrier to delivery drugs• To avoid the barrier, painless microneedles can puncture

the skin with micron size holesthe skin with micron-size holes• Microneedles can potentially include drugs

stratum corneum

stratum corneum

stratum

papillary layercapillary networkcorneum

bloodcirculation

microneedle

corneum

punctured holescorneum

DRUG

uptakepermeation

uptake

permeation


Epidermis Dermis Subdermaltissue

DRUG

Epidermis DermisDRUG permeation

EpidermisPuncture process


µSL Applications IV Microneedles for transdermal drug delivery

µSL Applications IV

~460 µm60 µ

~160 µm


Choi, J.W., Irwin, M., Wicker, R.B., Proc. of SPIE, Photonics West, Jan. 23-28 2010, San Francisco, CA, 7596: 75960H-1~11.


µSL Applications V Microlens arrays for optics

µSL Applications V

• collimating light in an optoelectronic sensor, an optical communication device, and confocal microscopes


Park, I.B., Lee, S.D., Kwon, T.W., Choi, J.W., Lee, S.H. Journal of the Korean Society for Precision Engineering, 25: 123-130, 2008.


µSL Applications VI Nerve guidance conduits (NGCs)

µSL Applications VI

• To support peripheral nerve regeneration• Using poly(ethylene glycol) (PEG) with the molecular

weight of 3400 (non toxic)weight of 3400 (non-toxic)


Choi, J.W., Irwin, M., Wicker, R.B., Proc. of SPIE, Photonics West, Jan. 23-28 2010, San Francisco, CA, 7596: 75960H-1~11.


Current WorkCurrent Work



Current Work ICurrent Work ITITLE: Multi-scale, multi-material additive manufacturing and its application

Continuous projection for multi-

Optical fiberCollimating lens

DMD board Focusing unitPrismprojection for multi

scale fabrication Automatic material

LampTube lens

Automatic material changeover

Automatic washing Reflecting mirrorX-Y stage

Cleaning system

Objective lensgmechanism Z stage

Pump system Vat for used materialSmall vat

Objective lens


p y


Current Work IICurrent Work IITITLE: Low-Temperature, Low-Cost Direct Writing of Photocrosslinkable Solutions Filled with Copper Nanoparticles for 3D Conductive Patterns on Flexible Substrates

Using geometry-controlled nanoparticles

Copper nanoparticles in photocrosslinkable solution

Microstereolithography process with material changeover

Final 3D conductive patterns on a flexible substrate


photocrosslinkable solution material changeover on a flexible substrate


Current Work IIICurrent Work IIITITLE: Multi-Material, Large-Area Microstereolithography of Biodegradable/Biocompatible

3D Microneedle Arrays for Long-Term, Sustained, and Controlled Drug Release



Current Work IVCurrent Work IVTITLE: Direct Writing with Micro/Macro Stereolithography for 3D Electronics



Collaborators Dr. Ryan Wicker, UTEP – AM, DW Dr. Eric MacDonald, UTEP – 3D electronics

Collaborators

Dr. Eric MacDonald, UTEP 3D electronics Dr. Namsoo Kim, UTEP – Nanoparticle synthesis, Packing technology Dr. Karina Arcaute, UTEP – Nerve Guidance Conduits Dr. Kenneth Church, UTEP, nScript – Micro-dispensingDr. Kenneth Church, UTEP, nScript Micro dispensing Dr. Michael Irwin, UTEP – Chemistry, Biomaterials Dr. Brenda Mann, Univ. of Utah – Poly (ethylene glycol) synthesis Dr Brent Stucker Univ of Louisville – Ultrasonic Consolidation (UC) Flexible FDMDr. Brent Stucker, Univ. of Louisville Ultrasonic Consolidation (UC),Flexible FDM Dr. Jun Sakakibara, Tsukuba Univ., Japan - Fluidics Dr. Seokhee Lee, Pusan Nat’l Univ., Korea - µSL, Automation Dr Changsik Ha Pusan Nat’l Univ Korea – PolymerDr. Changsik Ha, Pusan Nat l Univ., Korea Polymer Dr. Kyunghyun Choi, Cheju Nat’l Univ., Korea – DW, Printed OLDE Dr. Hochan Kim, Andong Nat’l Univ., Korea – Automation, Software development Dr Inhwan Lee Chungbuk Nat’l Univ Korea - µSL Bioreactor


Dr. Inhwan Lee, Chungbuk Nat l Univ., Korea µSL, Bioreactor


Acknowledgements Several photos and materials has been obtained from W.M. Keck Center at UTEP

(PI, Dr. Ryan Wicker).

Acknowledgements

( y ) Several photos has been copied from the Wikipedia website for better

understanding. Several photos and materials has been obtained from the web-based lecture

materials.


Documents

IDML Introduction