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Design Alternatives for Design Alternatives for Micropatterning of Micropatterning of MacromoleculesMacromolecules
Design a system that facilitates cell Design a system that facilitates cell deposition and micropatterning to be used deposition and micropatterning to be used in the creation of cellular and polymer in the creation of cellular and polymer based circuits.based circuits.
Customer CriteriaCustomer Criteria Suitable for printing proteins for cell Suitable for printing proteins for cell
adhesionadhesionFibronectinFibronectinCollagen IVCollagen IVCollagen I –fluorescence labeled Collagen I –fluorescence labeled Laminin Laminin
Biocompatible/Sterile Biocompatible/Sterile Prints accurate & precise patternsPrints accurate & precise patterns
High resolutionHigh resolution Cost-effective (<$500)Cost-effective (<$500)
Neural cell patterning1
Design AlternativesDesign Alternatives
Each alternative design consists of a Droplet-Each alternative design consists of a Droplet-Depositing-Device (DDD), Substrate-Positioning-Depositing-Device (DDD), Substrate-Positioning-Device (SPD), and Solution-Supplying-Device (SSD) Device (SPD), and Solution-Supplying-Device (SSD) that may or may not be the samethat may or may not be the same
Resolution- 635 dpiResolution- 635 dpi Diameter of droplet (2R): Diameter of droplet (2R):
20um20um Separation of drops (e): 20-Separation of drops (e): 20-
25um25um
Assessment of Design Alternatives Assessment of Design Alternatives
DDD: DDD: For a resolution of 635 dpi, it is necessary to minimize the printed For a resolution of 635 dpi, it is necessary to minimize the printed
droplet diameterdroplet diameterVelocity of Droplet (Ejection Frequency) Velocity of Droplet (Ejection Frequency) Surface tension and viscosity of solutionSurface tension and viscosity of solution
Clogging should be preventedClogging should be preventedPrevent ink spray phenomenonPrevent ink spray phenomenon
SPD:SPD: Movement of substrate should be minimized for high resolution Movement of substrate should be minimized for high resolution System should allow for uniquely dimensioned substrates to printed onSystem should allow for uniquely dimensioned substrates to printed on
SSD:SSD: Could make system robust for different viscosities and surface tensions Could make system robust for different viscosities and surface tensions
Different static pressuresDifferent static pressures Clogging should be preventedClogging should be prevented
Software handling for all three should be feasibleSoftware handling for all three should be feasible
Ink CartridgeInk Cartridge Can’t control pressure where the ink leaves cartridge Can’t control pressure where the ink leaves cartridge It is difficult to decontaminate printer cartridgeIt is difficult to decontaminate printer cartridge Difficult to prevent protein loss in the porous membrane of Difficult to prevent protein loss in the porous membrane of
an ink cartridge (clogging)an ink cartridge (clogging)
Height Controlled ReservoirHeight Controlled Reservoir Variation in potential energy will yield different pressuresVariation in potential energy will yield different pressures Easily decontaminatedEasily decontaminated Clogging is not an issue Clogging is not an issue
Syringe PumpSyringe Pump Could be used to change pressure; because, small Could be used to change pressure; because, small
displacements yield large pressure changesdisplacements yield large pressure changes Clogging and Contamination can be easily resolved with a Clogging and Contamination can be easily resolved with a
Stationary print Stationary print head (DDD)head (DDD) PiezoelectricPiezoelectric
Software is Software is availableavailable
System that uses stationary piezoelectric print head to deposit solution onto motorized X-Y stage1
X-Y Printing SystemX-Y Printing System
Piezoelectric head (DDD):Piezoelectric head (DDD): MicroFab:MicroFab:
Printed droplet diameter is 65um Printed droplet diameter is 65um (MIT(MIT11))
Separation of droplets is 10umSeparation of droplets is 10um Maximum ResolutionMaximum Resolution
is 339dpiis 339dpi Cost is $500Cost is $500
Can increase resolution by Can increase resolution by coupling the ejection of the coupling the ejection of the droplets with the movement of droplets with the movement of the boardthe board
Piezo drop-on-demand print head1
X-Y Printing SystemX-Y Printing System
•X-Y Movement (SPD)
Movement of X-Y stage relative to droplet velocity
X-Y Printing SystemX-Y Printing SystemModelModel PricePrice ResolutionResolution SpeedSpeedAB Tech AB Tech Mini X-Y Linear Motor Mini X-Y Linear Motor Positioning StagePositioning Stage
0.5 0.5 μμmm 100+ mm/s100+ mm/s
Newmark Systems inc.Newmark Systems inc.NLS4 SeriesNLS4 Series
Separation of droplets is .25mmSeparation of droplets is .25mm
Maximum Resolution is 100dpiMaximum Resolution is 100dpi Software CapabilitiesSoftware Capabilities
Printer head element may only Printer head element may only change the ejection frequencychange the ejection frequency
Droplet size can not be changedDroplet size can not be changed Voltage through resistor is constantVoltage through resistor is constant
HP 550C3
Thermal Inkjet PrintersThermal Inkjet PrintersCan’t change the size of the droplet since Can’t change the size of the droplet since pressure in channel or the voltage pressure in channel or the voltage applied to the resistor is predetermined applied to the resistor is predetermined for the particular ink solutionfor the particular ink solution
The water-based ink becomes superheated (far above its normal boiling point) and finally reaches the critical temperature for bubble nucleation at around 280 °C. At this At this point no further heat is applied to the point no further heat is applied to the bubblebubble
Vapor bubble expands until all of the Vapor bubble expands until all of the heat stored in excess to the boiling heat stored in excess to the boiling point is used to convert liquid to point is used to convert liquid to vapor. Once the excess heat is vapor. Once the excess heat is removed, the bubble collapses on to removed, the bubble collapses on to the resistor, which is no longer being the resistor, which is no longer being heated.heated.
The bubble expansion and formation The bubble expansion and formation sequence occurs in 10us. Then there sequence occurs in 10us. Then there must be a minimum dwell time of must be a minimum dwell time of 100-500us to enable the channel to 100-500us to enable the channel to be refilled through capillary actionbe refilled through capillary action
Maximum ejection frequency is Maximum ejection frequency is 50kHz50kHz
Print head (DDD)Print head (DDD) Built-in Caddy System (SPD)Built-in Caddy System (SPD)
Necessary to print on our substrateNecessary to print on our substrate Resolution of 5760x1440 dpi Resolution of 5760x1440 dpi
Maximum Diameter of Droplet Maximum Diameter of Droplet (4.5um)(4.5um)Diameter of droplet based on Diameter of droplet based on experimentsexperiments
Microencapsulation group achieved Microencapsulation group achieved a resolution of 254dpi (diameter of a resolution of 254dpi (diameter of droplet 100um)droplet 100um)
SoftwareSoftwareUse default Use default Modify voltage supply to actuatorModify voltage supply to actuator
AdvantagesAdvantages Caddy-ready systemCaddy-ready system High resolutionHigh resolution
Greater than 1200dpiGreater than 1200dpi77 Can vary pressure in Can vary pressure in
channelchannelMight be necessary for Might be necessary for solutions of different solutions of different viscosities and surface viscosities and surface tensions tensions
DisadvantagesDisadvantages Difficult to modify Difficult to modify
software software EPROM based EPROM based Microprocessor to work Microprocessor to work in conjunction with in conjunction with different power supply different power supply settingssettings
Ink SolutionInk SolutionHow do we increase the How do we increase the resolution?resolution?
Current inks have a Current inks have a surface tension of 3surface tension of 33.3.5 5 dyn/cm (0.0335N/m) dyn/cm (0.0335N/m) and a viscosity of 7.4 and a viscosity of 7.4 cP at 20 ◦CcP at 20 ◦C
The surface tension of The surface tension of water (73 dyne/cm) water (73 dyne/cm) would increase the would increase the force required to force required to deform dropletdeform droplet
Leading to an Leading to an increase in resolutionincrease in resolution
Viscosity of water Viscosity of water (0.89cp) would (0.89cp) would decrease the time decrease the time required to wet the required to wet the surfacesurface
Leading to a Leading to a decrease in decrease in resolutionresolution
Experimental ProtocolExperimental Protocol
Hypothesis:Hypothesis: By increasing the concentration of proteins in our By increasing the concentration of proteins in our
solution, the viscosity of our ink will increase; hence, solution, the viscosity of our ink will increase; hence, we will achieve higher resolutionwe will achieve higher resolution
By increasing the surface tension, we will prevent By increasing the surface tension, we will prevent wetting of our substratewetting of our substrate
A high surface tension means low attraction and a low A high surface tension means low attraction and a low surface tension means a high degree of attraction surface tension means a high degree of attraction
Image printed solution of fluorescent collagen Image printed solution of fluorescent collagen (type I)(type I) fluorescence microscopy fluorescence microscopy
Low Cost (105) Low Cost (105) Print Head Print Head
Movement System Movement System
ReferencesReferences
1.1. Sanjana NE, et.al. A fast flexible ink-jet method for patterning dissociated neurons Sanjana NE, et.al. A fast flexible ink-jet method for patterning dissociated neurons in culture. J Neurosci Meth (2004); 136: 151-163.in culture. J Neurosci Meth (2004); 136: 151-163.
2.2. Boland T, et al. Cell and organ printing 1: protein and cell printers.Boland T, et al. Cell and organ printing 1: protein and cell printers.Anat Rec A Discov Mol Cell Evol Biol. 2003 Jun;272(2):491-6. Anat Rec A Discov Mol Cell Evol Biol. 2003 Jun;272(2):491-6.
3.3. ““HP 550C.” PC Universe (2005). <http://www.pcuniverse.hpsupplieslink.com>. 16 HP 550C.” PC Universe (2005). <http://www.pcuniverse.hpsupplieslink.com>. 16 Nov. 2005.Nov. 2005.
4.4. ““An idiot's guide to making a CD printer from an Epson 640.” VideoHelp.com An idiot's guide to making a CD printer from an Epson 640.” VideoHelp.com (2005) <http://www.videohelp.com/forum/viewtopic.php?t=177053> 15 Nov. 2005.(2005) <http://www.videohelp.com/forum/viewtopic.php?t=177053> 15 Nov. 2005.
6.6. US Patent Office <http://www.uspatent.org>US Patent Office <http://www.uspatent.org>
7.7. Setti L et al., An amperometric glucose biosensor prototype fabricated by thermal Setti L et al., An amperometric glucose biosensor prototype fabricated by thermal ink jet printing. Biosen & Bioelec 20 (2005) 2019-2026. ink jet printing. Biosen & Bioelec 20 (2005) 2019-2026.