Amplifier system and controls for dielectrophoretic tracking in microfluidic devices

Patent metadata

Field	Value
Publication number	US-12297481-B2
Application number	US-202217750880-A
Country	US
Kind code	B2
Filing date	May 23, 2022
Priority date	Oct 9, 2014
Publication date	May 13, 2025
Grant date	May 13, 2025

Abstract

Systems, methods, and devices are described herein for identifying, monitoring, isolating, or selecting a cell having a predefined characteristic in a mixed population of cells utilizing a combination of any one or more of iDEP, a region of localized field enhancement, a variable frequency electric field, a wide bandwidth amplifier, and/or an imaging apparatus.

First claim

We claim:

1. A system comprising a paired and counter-phase amplifier unit coupled to electrodes in a dielectrophoresis microfluidic device, the system comprising:
the dielectrophoresis microfluidic device comprising:
an elongate channel having an inlet defining a first end, and an outlet defining a second end, and having at least one spatially localized high-field region configured to provide translation of a particle or cell in an insulator dielectrophoresis (iDEP) control operation; and
the electrodes comprising a first electrode and a second electrode located in the dielectrophoresis microfluidic device to generate a spatially non-uniform electric field at the at least one spatially localized high-field region;

the paired and counter-phase amplifier unit comprising:
a wideband splitter unit adapted to generate counter-phase input signals comprising a first signal and a second signal from an input signal, wherein the second signal is 180° phase-shifted from the first signal; and
wideband power amplifiers comprising a first amplifier and a second amplifier, wherein an input of the first amplifier is coupled to a first output of the wideband splitter unit to receive the first signal, and wherein an input of the second amplifier is coupled to a second output of the wideband splitter unit to receive the second signal, and wherein the first amplifier and second amplifier are configured to generate counter-phase output signals applied to the first and second electrodes by amplifying a voltage difference between the first signal and the second signal to an output voltage twice that of individual outputs of the first and second signals at a range between, and inclusive of, 20 V and 1000 V, and wherein the counter-phase output signals have a frequency between, and inclusive of, 0.01 MHz and 10 MHz; and

an adjustable power supply operably connected with the paired and counter-phase amplifier unit and configured for feedback control for a constant power output for the insulator dielectrophoresis control operation.

2. The system of claim 1 , wherein each of the first and second electrodes is located outside the at least one spatially localized high-field region.

3. The system of claim 2 , wherein the system is configured for single particle tracking.

4. The system of claim 3 , wherein the system is configured for single particle dielectrophoretic translation of bio-particles under electric fields.

5. The system of claim 4 , wherein the paired and counter-phase amplifier unit is operably connected for electrical stimulation and measurements with the microfluidic device and the single particle trapping is performed in one or more insulator constriction regions in the dielectrophoresis microfluidic device.

6. The system of claim 1 , wherein the adjustable power supply is self-adjustable, via the feedback control, for dynamic modulation of supply voltages in response to measurements from the dielectrophoresis microfluidic device.

7. The system of claim 6 , wherein the paired and counter-phase amplifier unit is configured to deliver the constant power output for avoiding over-heating and signal distortion due to signal saturation.

8. The system of claim 7 , wherein the paired and counter-phase amplifier unit is configured to reduce dynamic distortions and parasitic voltage drops within the counter-phase output signals of the first and second amplifiers.

9. The system of claim 1 , wherein the at least one spatially localized high-field region comprises insulator constrictions or field non-uniformities.

10. The system of claim 9 , wherein the system is configured to position and measure cells within respective media in the at least one spatially localized high field region.

11. The system of claim 1 , wherein the first and second amplifiers are provided with the first and second signals each having a same amplitude.

12. The system of claim 1 , wherein the first and second amplifiers are each operational amplifiers (Op-amps).

13. The system of claim 1 , wherein the wideband splitter unit comprises super-fast low-power Op-amps.

14. The system of claim 1 , further comprising an attenuator and a controllable signal generator, wherein the controllable signal generator is connected to the first amplifier and the second amplifier to provide a source signal for the counter-phase output signals.

15. The system of claim 1 , wherein each of the first and second amplifier has a slew rate of over 2500 V/μs to provide the counter-phase output signals with a slew rate of over 5000 V/μs.

16. The system of claim 1 , wherein each of the first and second amplifier has a slew rate of over 3000 V/μs to provide the counter-phase output signals with a slew rate of over 6000 V/μs.

17. The system of claim 1 , wherein each of the first and second amplifier has a slew rate of over 4000 V/μs to provide the counter-phase output signals with a slew rate of over 8000 V/μs.

18. The system of claim 1 , wherein each of the first and second amplifier has a slew rate of 5000 V/μs to provide the counter-phase output signals with a slew rate of 10000 V/μs.

19. The system of claim 1 , wherein the paired and counter-phase amplifier unit is operably connected with the dielectrophoresis microfluidic device and is configured to output at a high voltage and a high frequency selected from the group consisting of: 300 V pp at 100 KHz, 300 V pp at 1 MHz, 300 V pp at 3 MHz, and 250 V pp at 5 MHz.

20. The system of claim 1 , wherein the first and second electrodes are configured to focus and concentrate particles in a flowing aqueous suspension.

Assignees

• Univ Virginia Patent Foundation

Inventors

• Swami Nathan
• Rohani Ali
• Farmehini Vahid
• Varhue Walter

Classifications

• B03C5/005

  Dielectrophoresis, i.e. dielectric particles migrating towards the region of highest field strength · CPC title

• G01N33/56911

  Bacteria · CPC title

• G01N33/487

  of liquid biological material · CPC title

• B03C2201/26

  for use in medical or biological applications · CPC title

• B03C5/026 Primary

  using open-gradient differential dielectric separation, i.e. using electrodes of special shapes for non-uniform field creation, e.g. Fluid Integrated Circuit [FIC] · CPC title