Insulator Based Dielectrophoresis Dielectrophoresis ( (iDEP iDEP): - PowerPoint PPT Presentation

Insulator Based Dielectrophoresis Dielectrophoresis ( (iDEP iDEP): ): Insulator Based A Tool to Detect, Separate and Concentrate A Tool to Detect, Separate and Concentrate Aerosolized Biological Particles Aerosolized Biological Particles Morales a a , William D. Munslow b b , Alfredo M. Morales , William D. Munslow , Alfredo M. b , Blake A. a Scott M. Maurer Maurer b , Blake A. Simmons Simmons a Scott M. a Sandia National Laboratories, Livermore, CA 94550 a Sandia National Laboratories, Livermore, CA 94550 b Lockheed Martin MS2, Manassas, VA 20110 b Lockheed Martin MS2, Manassas, VA 20110 Authorized for Unlimited Public Release by SNL SAND2009- -3326C 3326C Authorized for Unlimited Public Release by SNL SAND2009 And by LMC BAL200902002- -02 02 And by LMC BAL200902002 NBC 2009 Symposium NBC 2009 Symposium Jyvä Jyv äskyl skylä ä, Finland , Finland 8 – – 11 June 2009 11 June 2009 8

Biological Sensor Requirements Biological Sensor Requirements • Requirements and Performance Measures: • Requirements and Performance Measures: Affordability - - Early detection Early detection - - Low false alarm rate Low false alarm rate Affordability • Current Biological Detection System Deficiencies: Current Biological Detection System Deficiencies: • Expensive - - Hours/days for analysis Hours/days for analysis - - Sensitivity Sensitivity vs vs false alarm rate false alarm rate Expensive • Desirable Characteristics of Typical Detect Desirable Characteristics of Typical Detect- -to to- -Warn Sensor: Warn Sensor: • Spider Charts: metrics shown by length of legs Spider Charts: metrics shown by length of legs Detection Confidence Detection Confidence Detection Confidence Ideal Biological Detection System: Ideal Biological Detection System: 98 98 98 Sensitivity Sensitivity Sensitivity Response Time (min) Response Time (min) Response Time (min) (ACPLA) (ACPLA) (ACPLA) 95 95 95 • Low cost, low consumables and simple • Low cost, low consumables and simple 1 1 1 1 1 1 0 0 0 0 0 0 2 2 2 1 1 1 , , , 0 0 0 0 0 0 90 90 90 0 0 0 operation operation 1 1 1 4 4 4 0 0 0 . . . 0 0 0 0 0 0 0 0 0 • Operational flexibility: Configurable as either Operational flexibility: Configurable as either • 1000 1000 1000 100 100 100 10 10 10 Size (m 3 ) Size (m 3 ) Size (m 3 ) FAR (per year) FAR (per year) FAR (per year) 1 1 1 .1 .1 .1 .5 .5 .5 detect- -to to- -warn or as a detect warn or as a detect- -to to- -treat system treat system detect 1 1 1 . . . 5 5 5 4 4 4 • Expensive bioassays may be used if • Expensive bioassays may be used if 1 1 1 1000 1000 1000 . . . 0 0 0 26 26 26 0 0 0 . . . 5 5 5 inexpensive orthogonal triggers limit the inexpensive orthogonal triggers limit the 500 500 500 52 52 52 Maintenance Maintenance Maintenance Unit Cost ($M) Unit Cost ($M) Unit Cost ($M) Interval (wks) Interval (wks) Interval (wks) 100 100 100 number of times bioassays are run number of times bioassays are run Operating Cost ($/year) Operating Cost ($/year) Operating Cost ($/year) 2

Why an iDEP iDEP Approach? Approach? Why an - + 1000 VDC 750 VDC 500 VDC Flow Separation by size: 2 μ m (green) and 1 μ m (red) Time Flow Bacillus subtilis - + spores (red) trapped. 1 μ m polystyrene Time beads (green) pass. Lapizco-Encinas, B. H.; Simmons, B.A., et al. , Anal. Chem. 2004, 76, 1571-1579 iDEP Selectively Traps Particles and May be Used as a Trigger iDEP Selectively Traps Particles and May be Used as a Trigger 3

iDEP Can Concentrate Bacteria Selectively Can Concentrate Bacteria Selectively iDEP • iDEP iDEP Separation of Live B. Separation of Live B. subtilis subtilis and B. cereus (similar bacteria) and B. cereus (similar bacteria) • • Mechanism: Different Size and Shape • Mechanism: Different Size and Shape • Also Separated E. coli, B. cereus, B. • Also Separated E. coli, B. cereus, B. subtilis subtilis, B. , B. megaterium megaterium, B. , B. subtilis subtilis spores, TMV virus, and polystyrene particles of various sizes spores, TMV virus, and polystyrene particles of various sizes 80 Minimum E required for DEP trapping (V/mm) medium conductivity = 2.2 microS/mm Solution Conductivity=2.2microS/cm Solution Conductivity=2.2microS/cm 70 medium conductivity = 10.4 microS/mm Solution Conductivity=10microS/cm Solution Conductivity=10microS/cm 60 50 40 - + 30 20 10 0 E. coli B. megaterium B. subtilis B.cereus E. coli < B. megaterium < B. subtilis < B. cereus Selectively trapping B. cereus (green) Lapizco-Encinas, B. H.; Simmons, B.A., et al. , while passing B. subtilis (red) Electrophoresis 2004, 25,1695-1704. 4

iDEP is a Physically Selective Phenomenon is a Physically Selective Phenomenon iDEP • DEP: Motion of Conductive Object Toward • DEP: Motion of Conductive Object Toward (away from) High Electric Field (away from) High Electric Field + + Nonuniform electric field Nonuniform electric field – – Along electric field gradients Along electric field gradients – – Nonlinear in the applied electric field Nonlinear in the applied electric field Electrode Electrode Electrode Electrode - - - - • DEP Force Proportional to: DEP Force Proportional to: • + + - - + + + + - - – – Particle volume Particle volume Higher charge density – Conductivity + polarizability polarizability difference difference – Conductivity + Net movement Net movement between particle and liquid between particle and liquid     Lower charge density Lower charge density ~ ~       3 2 F 2 r Re f , E DEP o m p m              For Vdc, f ( , ) 2 p m p m p m Sabounchi, P.; Morales, A.M. et al. Biomed Microdevices, 2008, 10, 661–670. • DEP Force depend on: • DEP Force depend on:  p Conductivity of the particle,  – – Conductivity of the particle, p Conductivity of the medium,   m – – Conductivity of the medium, m iDEP Uses Insulating Post Uses Insulating Post iDEP Size of the particle, r r – – Size of the particle, Features to Shape E- -field field Features to Shape E 5

iDEP with Pressure Driven Flow with Pressure Driven Flow iDEP • Large Sample Volumes Must be Processed for Many Clinical Applica • Large Sample Volumes Must be Processed for Many Clinical Applications tions • Only Pressure Driven Flow can Process Such Volumes Only Pressure Driven Flow can Process Such Volumes • du      particle Pressure Driven m - ( u U ) F particle Flow Profile dt Force due to flow        u U E E E ( ) particle EK DEP iDEP Force Electrokinetic Electrokinetic Dielectrophoretic Dielectrophoretic Fluid Flow Fluid Flow Velocity Velocity Velocity Velocity Electrokinetic Flow • Potential Attributes of Biological • Potential Attributes of Biological Profile Sensor Incorporating iDEP Sensor Incorporating iDEP: : – – Affordability: iDEP iDEP trigger for bioassay trigger for bioassay Affordability: – – Early Detection: Response within Early Detection: Response within A Significant Amount of Work A Significant Amount of Work seconds of turning on seconds of turning on Done in the Lab. Done in the Lab. – Low False Alarm Rate: Orthogonal – Low False Alarm Rate: Orthogonal iDEP trigger trigger iDEP What Will it Take to Field iDEP iDEP? ? What Will it Take to Field 6

Micro- -molded molded iDEP iDEP Zeonor Zeonor Chips Chips Micro • Polymer Polymer iDEP iDEP Chips: Chips: • – Low Cost & Ease of Manufacture Low Cost & Ease of Manufacture – x y – Amenable to Large Scale Production – Amenable to Large Scale Production R 1 R 2 R 3 R 4 7

Chip Surface and Buffer Chemistry Is Critical Chip Surface and Buffer Chemistry Is Critical • Surface & buffer chemistry enable repeatable trapping with press Surface & buffer chemistry enable repeatable trapping with pressure driven flow ure driven flow • OR O O OH O + NaIO 4 + OH O O 8 MOPA “Chip polymer” Functionalized “chip polymer” (Methoxy polyethylene glycol acrylates) Without MOPA • MOPA Treatment Lowers Contact angle, • MOPA Treatment Lowers Contact angle,  2  4 90  65  2° ° w/o MOPA w/o MOPA vs vs 65 4° ° w/ MOPA w/ MOPA 90 • Background Buffer pH Adjusted to 8 • Background Buffer pH Adjusted to 8 While Keeping Conductivity Low While Keeping Conductivity Low With • Compatible with TWEEN used in • Compatible with TWEEN used in MOPA Aerosol Sample Collector Aerosol Sample Collector 8

System Layout and Architecture System Layout and Architecture Aerosol Collector Test Sample Aerosol Collector Test Sample Background Buffer Background Buffer Waste Manifold Waste Manifold iDEP Chip Chip iDEP 9

Robust Automated iDEP iDEP System System Robust Automated • Designed a Robust System Capable of Operating in the Field • Designed a Robust System Capable of Operating in the Field • Both Software & Hardware were Simplified and Optimized with • Both Software & Hardware were Simplified and Optimized with Reliability and Safety in Mind Reliability and Safety in Mind • Prototype Field Test Unit Fabricated, Integrated and Tested Prototype Field Test Unit Fabricated, Integrated and Tested • Modular iDEP chip holder 10