Methods and systems for identifying a particle using dielectrophoresis

Abstract

A system for identifying a particle. The system includes a microfluidic device; a microelectrode array including a plurality of electrodes, the microelectrode array disposed within the microfluidic device; a plurality of particles suspended in a solution and delivered to the micro-electrode array using the microfluidic device; a signal generator operatively coupled to the microelectrode array; a particle detector adjacent to the microelectrode array; and a controller in operative communication with the signal generator and the particle detector. The controller is configured to apply an oscillating voltage signal to the microelectrode array between a low frequency and a high frequency at a sweep rate, wherein the sweep rate is no more than a maximum sweep rate, and determine a distribution of the plurality of particles relative to the microelectrode array at a plurality of frequency levels between the low frequency and the high frequency.

1 . A system for identifying a plurality of particles suspended in a solution, the system comprising:
 a microfluidic device to receive the solution including the plurality of particles;   a microelectrode array comprising a plurality of electrodes, the microelectrode array disposed within the microfluidic device and in vicinity of the received solution, the microelectrode array including a first plurality of electrodes to provide a first charge and a second plurality of electrodes to provide a second charge, the second charge being different than the first charge, and the second plurality of electrodes being in a nonparallel relationship with the first plurality of electrodes;   a signal generator operatively coupled to the microelectrode array;   a particle detector adjacent to the microelectrode array; and   a controller in operative communication with the signal generator and the particle detector, the controller being configured to
 apply an oscillating voltage signal to the microelectrode array at a plurality of frequency levels varying continuously between a low frequency and a high frequency, the plurality of frequency levels being applied at a sweep rate, wherein the sweep rate is no more than a maximum sweep rate and is no less than a minimum sweep rate, the applying of the oscillating voltage signal to the microelectrode array resulting in a spatially non-uniform field, and 
 determine a distribution of the plurality of particles relative to the microelectrode array at the plurality of frequency levels varying continuously between the low frequency and the high frequency. 
   
     
     
         2 . The system of  claim 1 , wherein the solution has a conductivity and wherein the maximum sweep rate is a function of the conductivity. 
     
     
         3 . The system of  claim 2 , wherein the conductivity is 0.10 S/m and the maximum sweep rate is less than 0.0026 MHz/s. 
     
     
         4 . The system of  claim 2 , wherein the conductivity is 1.0 S/m and the maximum sweep rate is less than 0.0031 MHz/s. 
     
     
         5 . The system of  claim 1 , wherein the low frequency is 0.01 MHz and the high frequency is 2.0 MHz. 
     
     
         6 . The system of  claim 1 , wherein the particle detector comprises an image detector and an image analysis system and wherein the controller, to determine the distribution of the plurality of particles relative to the microelectrode array, is further configured to collect an image of the microelectrode array using the image detector and determine a spatially resolvable concentration of the plurality of particles relative to the microelectrode array using the image analysis system at each of the plurality of frequency levels. 
     
     
         7 . The system of  claim 1 , wherein, to determine the distribution of the plurality of particles relative to the microelectrode array, the controller is further configured to use an image analysis system to determine a first spatial distribution of the plurality of particles and a second spatial distribution of the plurality of particles at a second location at each of the plurality of frequency levels. 
     
     
         8 . The system of  claim 7 , wherein, to determine the first spatial distribution of the plurality of particles at a first location, the controller is further configured to use the image analysis system to determine an intensity of the plurality of particles at the first location. 
     
     
         9 . The system of  claim 7 , wherein, to determine the second spatial distribution of the plurality of particles at the second location, the controller is further configured to use the image analysis system to determine an intensity of the plurality of particles at the second location. 
     
     
         10 . The system of  claim 1 , wherein the microelectrode array is a quadrapole microelectrode array. 
     
     
         11 . The system of  claim 1 , wherein the plurality of particles comprise red blood cells. 
     
     
         12 . The system of  claim 1 , wherein the sweep rate is no less than the minimum sweep rate. 
     
     
         13 . The system of  claim 12 , wherein the minimum sweep rate is 0.0008 MHz/s. 
     
     
         14 - 30 . (canceled) 
     
     
         31 . The system of  claim 1 , wherein the system comprises a handheld device, the handheld device including the microfluidic device, the microelectrode array, the signal generator, the particle detector, and the controller.