Ink jetting firstname.lastname@example.org
Continuos ink jet (CIJ) Derby: Annu Rev. Mater.Res 2010
Numbers • nozzles 20-30 µm in diameter • droplet volumes 10-20 pl • pixel size on paper 50 µm • shooting frequency up to 10 kHz
Ink jet imaged P.Koltay (IMTEK, Freiburg) in Oosterbroek: Lab-on-a-Chip
Reynolds number (Re) • ratio of inertial to viscous forces • Re = ρνD/η • ρ = density of fluid (kg/m3) • ν = linear velocity (m/s) • D = dimension of the system, diameter (m) • η = viscosity of the fluid (Pa*s = kg/m*s) • viscosity is the quantity that describes a fluid's resistance to flow • small Re means large viscous forces
Weber number Transducers 2007 p.165
Ohnesorge number Transducers 2007 p.165
Fluidics (3) Transducers 2007 p.165
Ink properties (1) • ink viscosity: 8-15 mPa*s, 20 mPa*s limit (water 1 mPa*s) • surface tension: 28-35 mN/m, even 350 (water 72 mN/m) • higher temperature, viscosity down ( able to print high Mw polymers) • particles difficult: clogging
Ink properties (2) • Water-Based Ink Jet Ink • Ingredients Amount Function • Water 50%-90% Ink Solvent • Colourant 1%-15% Colour Source • Co-Solvent/Humectant 2%-20% Ink vehicle, prevents evaporation • Fixative/Penetrant 0%-10% Assist fixing the ink to substrate • Surfactant 0.1%-6% Surface tension and wetting • Resin 0.2%-10% Durability and adhesion • Biocide 0.02%-0.4% Prevents bacterial growth • Fungicide 0.01%-0.4% Prevents fungal growth • Buffering Agent 0.05%-1% Control ink pH level • Other 0.01%-1% Controls specific characteristics http://www.mrinkjet.com/inkreport.htm
Thermal ink jet MEMS Handbook
Arrays of nozzles Gad-el-Hak: MEMS Handbook
Graphic printing vs. Functional materials printing Functional materials perform something, • Conduct electricity • Respond to enzymes • Show iridicence • Bend mechanically • Host cells
Line definition: droplet spacing & overlap • Silver nanoparticle printing of conductor lines. • Droplets too sparsely • Wavyness still seen • Optimal • Too much liquid leads to bulging
Drop spreading & temperature Substrate temperature is a standard variable in ink jetting experiments. It directly affects surface tension and viscosity and therefore spreading on substrate.
Nanoparticle inks Murata
Ink jet etching I.M. Hutchings: Ink-jet printing in micro-mabufacturing, 4M/ICOMM 2009
3D ink jetting I.M. Hutchings: Ink-jet printing in micro-mabufacturing, 4M/ICOMM 2009
Competition:Laser-assisted maskless microdeposition Alemohammad: J. Micromech. Microeng. 18 (2008) 115015 (12pp)
Laser-assisted maskless microdeposition (2) Alemohammad: J. Micromech. Microeng. 18 (2008) 115015 (12pp)
MDDW: microdispensing deposition write The MDDW method makes patterns on the substrate by pumping the slurry of suspended nanometal powders. Since it does not rely on the spray mechanism but direct contacting mechanism, it allows to avoid or minimize the ink from oxidation or reduction during the printing process.
M3D: maskless mesoscalematerials deposition M3D method uses a mechanically or ultrasonically driven device to stir and mix the suspended nanometal powders injecting the slurry through an orifice as a mist with the help of an air injection mechanism. M3D and MDDW devices have been developed beyond the capability that the ink-jet method can perform in handling high viscous materials and they can even handle three-dimensional patterns.
Ink jet dichotomies • thermal vs. piezo • continuous vs. drop-on-demand (DoD) • free pressure vs. free flow boundary conditions • printing on porous vs. hard surfaces (paper vs. overhead transparency) • printing vs. film formation • 2D patterns vs. 3D structures • solutions vs. particle-containing inks
Creating cell patterns Ink jet printing of PLGA polymer on PS substrate. Cells attach to PLGA but not on PS.
Promise: fewer process steps faster, cheaper electronics Murata et al: Microsyst Technol (2005) 12: 2–7
Applications: antennas (c) Inductive coil printed on fabric. (d) RFID antenna with metallic joints printed on paper. S M Bidoki, D M Lewis, M Clark, A Vakorov, P A Millner and D McGorman: J. Micromech. Microeng. 17 (2007) 967–974
Applications: 3D Antenna print on a combat helmet surface by the MDDW technique. N. S. Kim, A. K. Amert, S. M. Woessner, S. Decker, S. M. Kang, and K. N. Han International Conference on Nano Science and Nano Technology, GJ-NST 2006, Korea Institute Industrial Technology,Gwangju, South Korea, 7–8 December 2006. Ko & Grigoropoulos: JMM 2010 125010
Printing metallization I.M. Hutchings: Ink-jet printing in micro-mabufacturing, 4M/ICOMM 2009
Printing insulators I.M. Hutchings: Ink-jet printing in micro-mabufacturing, 4M/ICOMM 2009
Printing polymers I.M. Hutchings: Ink-jet printing in micro-mabufacturing, 4M/ICOMM 2009
Printing further I.M. Hutchings: Ink-jet printing in micro-mabufacturing, 4M/ICOMM 2009