Microfluidic dielectrophoresis system

Abstract

A microfluidic dielectrophoresis system, at least including one supply device for a liquid medium having particles contained therein, N≧2 microfluidic, dielectrophoretically active channels, which are equipped with electrodes, lines for the fluidic connection of the supply device to the channels, for the connection of the channels to one another, and for the drainage of the medium and/or the particles from the channels, and valves for setting the flow direction of the medium in the lines, the dielectrophoretically active channels being situated and being connected by lines in such a way that they may be operated connected in parallel and in series by switching the valves in relation to the flow direction of the medium and the electrodes of the various channels are activatable independently of one another. In addition, the present invention relates to the use of a microfluidic dielectrophoresis system according to the present invention and a method for performing a dielectrophoresis.

1 . A microfluidic dielectrophoresis system, comprising:
 a supply device for a liquid medium having particles contained therein,   N≧2 microfluidic, dielectrophoretically active channels (K n , where 1≦n≦N), which are equipped with electrodes,   lines for fluidic connection of the supply device to the channels (K n ), for connection of the channels (K n ) to one another, and for drainage of the medium or the particles from the channels (K n ), and   valves for setting a flow direction of the medium in the lines,   
       wherein the dielectrophoretically active channels (K 1  to K N ) are situated and are connected by lines in such a way that they may be operated connected in parallel or in series by switching the valves in relation to the flow direction of the medium, and the electrodes of the various channels (K 1  to K N ) are activatable independently of one another. 
     
     
         2 . The microfluidic dielectrophoresis system as recited in  claim 1 , wherein the dielectrophoretically active channels (K 1  to K N ) are situated together on a microfluidic element, or the dielectrophoretically active channels (K 1  to K N ) are situated on different microfluidic elements. 
     
     
         3 . The microfluidic dielectrophoresis system as recited in  claim 2 , wherein the microfluidic element(s) is a microfluidic chip. 
     
     
         4 . The microfluidic dielectrophoresis system according to  claim 1 , wherein the supply device is an injector pump, a peristaltic pump, or a micropump. 
     
     
         5 . The microfluidic dielectrophoresis system according to  claim 2 , wherein the supply device is an injector pump, a peristaltic pump, or a micropump. 
     
     
         6 . The microfluidic dielectrophoresis system as recited in  claim 1 , wherein at least one of the microfluidic dielectrophoretically active channels (K 1  to K N ) contain mixer structures. 
     
     
         7 . The microfluidic dielectrophoresis system as recited in  claim 2 , wherein at least one of the microfluidic dielectrophoretically active channels (K 1  to K N ) contain mixer structures. 
     
     
         8 . The microfluidic dielectrophoresis system as recited in  claim 4 , wherein at least one of the microfluidic dielectrophoretically active channels (K 1  to K N ) contain mixer structures. 
     
     
         9 . The microfluidic dielectrophoresis system as recited in  claim 1 , wherein the microfluidic channels (K 1  to K N ), which are equipped with electrodes, are implemented as at least two groups (K n,A  where 1≦n≦N and N≧2) and (K m,B  where 1≦m≦M and M≧2), which are connected one downstream from the other in the flow direction of the medium, the groups (K n,A  and K m,B ) being operated using electrode voltages of different frequencies or amplitudes. 
     
     
         10 . The microfluidic dielectrophoresis system as recited in  claim 2 , wherein the microfluidic channels (K 1  to K N ), which are equipped with electrodes, are implemented as at least two groups (K n,A  where 1≦n≦N and N≧2) and (K m,B  where 1≦m≦M and M≧2), which are connected one downstream from the other in the flow direction of the medium, the groups (K n,A  and K m,B ) being operated using electrode voltages of different frequencies or amplitudes. 
     
     
         11 . The microfluidic dielectrophoresis system as recited in  claim 4 , wherein the microfluidic channels (K 1  to K N ), which are equipped with electrodes, are implemented as at least two groups (K n,A  where 1≦n≦N and N≧2) and (K m,B  where 1≦m≦M and M≧2), which are connected one downstream from the other in the flow direction of the medium, the groups (K n,A  and K m,B ) being operated using electrode voltages of different frequencies or amplitudes. 
     
     
         12 . The microfluidic dielectrophoresis system as recited in  claim 6 , wherein the microfluidic channels (K 1  to K N ), which are equipped with electrodes, are implemented as at least two groups (K n,A  where 1≦n≦N and N≧2) and (K m,B  where 1≦m≦M and M≧2), which are connected one downstream from the other in the flow direction of the medium, the groups (K n,A  and K m,B ) being operated using electrode voltages of different frequencies or amplitudes. 
     
     
         13 . A method for dielectrophoresis for concentrating particles from a liquid medium using a microfluidic dielectrophoresis system as recited in  claim 1 , comprising:
 A) an accumulation phase, including the following steps   aa) switching the valves (a ij , b i ) to a parallel connection of the channels (K 1  to K N ),   ab) supplying medium having particles contained therein to the channels (K 1  to K N ),   ac) accumulating the particles in the channels (K 1  to K N ), a high-frequency AC voltage being applied to the electrodes;   B) a concentration phase, including the following steps   ba) switching the valves (a ij , b i ) to a series connection of channels (K 1  to K N ),   bb) releasing the accumulated particles by turning off the electrodes of the channels (K 1  to K N−1 ),   bc) transporting the released particles in or through the particular downstream channels (K n+1  to K N ), and   bd) collecting the particles in the channel (K N ) and   C) flushing the collected particles out of the channel K N .   
     
     
         14 . The method as recited in  claim 13 , wherein the concentration steps bb) releasing the accumulated particles in the channel (K N ) and bc) transporting the released particles into the particular downstream channel (K n+1 ) are performed by successively turning off the electrodes in the channels (K 1  to K N−1 ), beginning with the channel (K 1 ) through which the medium flows first. 
     
     
         15 . The method as recited in  claim 13 , wherein the microfluidic dielectrophoretically active channels (K n ), which are equipped with electrodes, are operated in at least two groups (K n,A  where 1≦n≦N and N≧2) and (K m,B  where 1≦m≦M and M≧2), which are connected one downstream from the other in the flow direction, using electrode voltages of different frequencies or amplitudes. 
     
     
         16 . The method as recited in  claim 14 , wherein the microfluidic dielectrophoretically active channels (K n ), which are equipped with electrodes, are operated in at least two groups (K n,A  where 1≦n≦N and N≧2) and (K m,B  where 1≦m≦M and M≧2), which are connected one downstream from the other in the flow direction, using electrode voltages of different frequencies or amplitudes. 
     
     
         17 . The method as recited in  claim 15 , wherein the concentration of particles is performed in each case in the last channels (K N,A  and K N,B ) of the groups through which medium flows, and these channels (K N,A  and K N,B ) are flushed out simultaneously or successively in a step CA) and CB). 
     
     
         18 . The method as recited in  claim 16 , wherein the concentration of particles is performed in each case in the last channels (K N,A  and K N,B ) of the groups through which medium flows, and these channels (K N,A  and K N,B ) are flushed out simultaneously or successively in a step CA) and CB).