Transcript Dielectrophoresis (DEP) - Northwestern University

Three-Dimensional
Dielectrophoresis Device with
Integrated Actuating and
Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
12/14/07
Lab on a chip
• Lab on a chip technology will reduce the
size of complex experimental setups.
• Eliminate large, bulky equipment.
• Move lab experiments to a non-lab
environment.
• Especially useful in biological and medical
fields for local use.
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Overview
• Device Overview
• Theory
– Dielectrophoresis (DEP)
– DEP cage actuation
– Impedance sensing
• Device Fabrication
• Previous Devices
• Results
– Parasitic Cages
– Particle Concentration
• Recommendations
– Micro-scale device
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Device Overview
• 1cm electrode strips
• Induced DEP Cages
• Top conductive
sealing layer
• Integrated actuation
and sensing
12/14/07
Medoro, G.; Manaresi, N.; Leonardi, A.; Altomare, L.; Tartagni, M.; Guerrieri, R. A Labon-a-Chip for Cell Detection and Manipulation. IEEE Sensors Journal, 2003, 3, 317-325
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Theory
Dielectrophoresis (DEP)
www-dsv.cea.fr/.../Image/Pascal/biopuces_64.jpg
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Theory
DEP – Governing Equation
F  2r  m Re[K ]E
3
2
• r – radius
• E – nonuniform electric field
•  m- permittivity of medium
• Re[K] – Clasius-Mossotti Factor where
 *p   m*
K *
 p  2 m*
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Theory
DEP - Permittivity

   j

*
• σ = conductivity of electric field
• ω = angular frequency of electric field
• Varying these two variables will alter the
permittivity of the particle/medium
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Theory
DEP - Clausius-Mossotti
• At low frequences:
• At high frequencies:
K
K
 p m
 p  2 m
 p  m
 p  2 m
• Polarization Factor (K) can be switched
between positive or negative values
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Theory
DEP – Vertical Forces
Iliescu, C.; Yu, L.; Xu, G.; Tay, F. A Dielectrophoretic Chip With a 3-D Electric Field
Gradient, Journal of Microelectromechanical Systems, 2006, 15, 1506-1513
• Buoyancy Force:
• DEP and Buoyancy:
12/14/07
4 3
FB  r  p   m g
3
2 p   m g
2
Re[K ]E 
3 m
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Theory
DEP – Ratio between DEP, Viscous forces
• FDEP = volume (~r3)
• Fviscous = surface (~r2)
FDEP
r
Fvisc
• Smaller particles will move slower
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Theory
DEP – Cage Actuation
• Progressively
alternating electrode
signals move particles
towards target electrode
• Provides better sensing
of particles
Medoro, G.; Manaresi, N.; Leonardi, A.; Altomare, L.; Tartagni, M.; Guerrieri, R. A Lab-on-a-Chip for
Cell Detection and Manipulation. IEEE Sensors Journal, 2003, 3, 317-325
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Theory
DEP – Cage Actuation
• The DEP Cages are able to move toward a target
electrode by moving the counter phase signal to the next
electrode closer to the target
Medoro, G.; Manaresi, N.; Leonardi, A.; Altomare, L.; Tartagni, M.; Guerrieri, R. A Lab-on-a-Chip for
Cell Detection and Manipulation. IEEE Sensors Journal, 2003, 3, 317-325
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Theory
Impedance Sensing
• To measure the concentration of particles impedance sensing is
used
• All electrodes are switched to ground except the sensing electrode
• The sensing electrode is connected to a transimpedance amplifier
Medoro, G.; Manaresi, N.; Leonardi, A.; Altomare, L.; Tartagni, M.; Guerrieri, R. A Lab-on-a-Chip for
Cell Detection and Manipulation. IEEE Sensors Journal, 2003, 3, 317-325
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Theory
Impedance Sensing – Transfer Function
• Transfer function of the transimpedance amplifier:
Vo
RF
( jw)  
Vi
RM
 1  jwRM C M

 1  jwR F C F



• RM and CM are the resistance and capacitance between
the electrode and lid
• RF and CF are the feedback resistance and capacitance
• There are two sensing frequency ranges, low and high, if
the same signal is used for both DEP cage formation
and sensing
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Theory
Impedance Sensing at low frequencies
• Low Frequency
– When w<<1/(RMCM) and w<<1/(RFCF) the sensing equation is:
Vo
RF

Vi
RM
– The Clausius Mossotti factor at low frequencies,
K
 p m
 p  2 m
shows that a particle will only be trapped in the DEP cage if its
conductivity is lower than the mediums giving rise to :
RMwp  RMwop
– These two equations show the output voltage will decrease with
particles at low frequencies
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Theory
Impedance Sensing at high frequencies
• High Frequency
– When w>>1/(RMCM) and w>>1/(RFCF) the sensing equation is:
Vo
CM

Vi
CF
– The Clausius Mossotti factor at high frequencies,
K
 p  m
 p  2 m
shows that a particle will only be trapped in the DEP cage if its
permittivity is lower than the mediums giving rise to :
C
wp
M
C
wop
M
– These two equations show the output voltage will decrease with
particles at high frequencies
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Original Fabrication
• No MEMS fabrication
methods used
• Printed Circuit Board
(PCB) techniques used
to attach electrodes
– Silk screened the
electrode pattern on to a
gold clad board
– etched away the
uncovered portion
– remove the screened
resist
Medoro, G.; Manaresi, N.; Leonardi, A.; Altomare, L.; Tartagni, M.; Guerrieri, R. A Lab-on-a-Chip for
Cell Detection and Manipulation. IEEE Sensors Journal, 2003, 3, 317-325
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Similar DEP Devices
• CMOS chip for individual cell manipulation
Manaresi, N.; Romani, A.; Medoro, G.; Altomare, L.; Leonardi, A.; Tartagni, M.; Guerrieri, R. A CMOS Chip for Individual Cell
Manipulation and Detection, IEEE Journal of Solid-State Circuits, 2003, 38, 12:2297-2305
• 102,400 actuation electrodes (20μm x 20μm)
• Capability of manipulating 10,000 cells in parallel
• Lack of integrated sensing technique
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Similar DEP Devices
• Dielectrophoretic Chip With a 3-D Electric Field Gradient
Iliescu, C.; Yu, L.; Xu, G.; Tay, F. A Dielectrophoretic Chip With a 3-D Electric Field Gradient, Journal of Microelectromechanical Systems, 2006, 15, 1506-1513
• Asymmetric 3D electric gradient achieved with specially configured
electrodes
• Thick electrodes integrated into vertical wall structures, thin planar
electrodes in bottom substrate
• Enhanced vertical DEP force (lower voltages and temperatures)
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Similar DEP Devices
• MEMS electrostatic particle transportation system
Desai, A.; Lee, S-W.; Tai, Y. A MEMS Electrostatic Particle Transportation System. Sensors and Actuators, 1999, 73, 37-44
• Electrostatic device capable of transporting particles in air
• Surface modifications performed to reduce adhesive forces
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Results
Parasitic Cages
• Parasitic Cages form between the two in-phase
electrodes, electrodes 3 and 4 in Figure (a)
• After actuating the DEP cage, a new parasitic cage will
form capturing the slow moving particles
Actuate the
DEP Cage
(a)
New parasitic
DEP Cage
(b)
Medoro, G.; Manaresi, N.; Leonardi, A.; Altomare, L.; Tartagni, M.; Guerrieri, R. A Lab-on-a-Chip for
Cell Detection and Manipulation. IEEE Sensors Journal, 2003, 3, 317-325
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Results
Parasitic Cages
Parasitic Cages
Medoro, G.; Manaresi, N.; Leonardi, A.; Altomare, L.; Tartagni, M.; Guerrieri, R. A Lab-on-a-Chip for
Cell Detection and Manipulation. IEEE Sensors Journal, 2003, 3, 317-325
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Results
Parasitic Cages – Minimize effects
Add intermediate step:
(a)
(b)
(c)
Medoro, G.; Manaresi, N.; Leonardi, A.; Altomare, L.; Tartagni, M.; Guerrieri, R. A Lab-on-a-Chip for
Cell Detection and Manipulation. IEEE Sensors Journal, 2003, 3, 317-325
• Creates a smaller chance slow moving particles
will be trapped in the attraction basin of the
parasitic cage
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Results
Parasitic Cages – Minimize effects
Reduce space between
electrodes:
• Space between
electrodes is nearly too
small for particles to fit
• Only possible using
MEMS fabrication
techniques due to small
spacing
12/14/07
Medoro, G.; Manaresi, N.; Leonardi, A.; Altomare, L.; Tartagni, M.; Guerrieri, R. A Labon-a-Chip for Cell Detection and Manipulation. IEEE Sensors Journal, 2003, 3, 317-325
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Results
Modeling Assumptions
• Cage distribution far too complicated to be
modeled at the level of individual particles
Assumptions
• Particle cloud within the DEP cage can be
modeled as homogenous
• Permittivity and Conductivity depend solely on
the ratio between the volume of microbeads and
suspending medium in the cylinder (distilled
water).
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Results
Signal Processing
Medoro, G.; Manaresi, N.; Leonardi, A.; Altomare, L.; Tartagni, M.; Guerrieri, R. A Lab-on-a-Chip for
Cell Detection and Manipulation. IEEE Sensors Journal, 2003, 3, 317-325
•Fixed pattern noise (FPN) removed by subtracting initial non-cage reading (a) from
cage reading, and then addition of average initial reading.
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Results
Optical observation
• Polystyrene microbeads,
3.46 µm diameter in H2O.
• 10 Vpp, 100 kHz
• 4 Concentration cycles
• Raw data on left
• Grayscale representation
of data on right
Medoro, G.; Manaresi, N.; Leonardi, A.; Altomare, L.; Tartagni, M.; Guerrieri, R. A Lab-on-a-Chip for
Cell Detection and Manipulation. IEEE Sensors Journal, 2003, 3, 317-325
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Results
Polystyrene Microbeads
• Electric field simulation in
FEMLAB in a 2-D plane
• Simulation performed for
initial concentration and 4
successive concentration
cycles
• Resistance translated to
voltage output with known
current
Medoro, G.; Manaresi, N.; Leonardi, A.; Altomare, L.; Tartagni, M.; Guerrieri, R. A Lab-on-a-Chip for
Cell Detection and Manipulation. IEEE Sensors Journal, 2003, 3, 317-325
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Results
S. cerevisia
• Experiment repeated with
S. cerevisiae yeast cells in
280-mM mannitol.
• Mannitol medium used to
prevent overheating due to
excessive conductivity
• S. cerevisiae displays
pDEP behavior above 200
kHz, electrolysis occurs at
less than 30 kHz
• Experiments performed at
100 kHz
12/14/07
Medoro, G.; Manaresi, N.; Leonardi, A.; Altomare, L.; Tartagni, M.; Guerrieri, R. A Lab-on-aChip for Cell Detection and Manipulation. IEEE Sensors Journal, 2003, 3, 317-325
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Base layer of SiO2 with photoresist on Silicon
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Mask pattern, inverted from intended electrode pattern
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Exposure to light – removal of photoresist.
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Dry plasma etching – removal of Silicon Oxide
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Removal of photoresist with acetone
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Ion implantation of electrode channels
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Removal of silicon oxide via plasma etching with CF4
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Lap polish of wafer to 50μm thickness
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Growth of SiO2 layers, removal from underside.
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Spin deposition of photoresist and mask placement
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Exposure to light - removal of photoresist
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Dry plasma etching – removal of Silicon Oxide
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Removal of photoresist with acetone
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• <110> wafer KOH through-etching of silicon wafer
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Removal of silicon oxide via plasma etching with CF4
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Combination of base electrode layer and reservoir layer
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Mated with wafer bonding over long electrodes, leaving
wire-connection ports exposed
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman
Recommendations
Micro-fabrication
• Mass production on a silicon wafer
• Glass cover with etched microchannel pattern and
common reservoir
12/14/07
Three-Dimensional Dielectrophoresis Device with Integrated Actuating and Impedance Sensing
Michael Beltran
Robert Lam
Bryan Lochman