Method and apparatus for fractionation using conventional dielectrophoresis and field flow fractionation

A method of discriminating matter, utilizing dielectrophoresis and field flow fractionation, in a chamber having an inlet port and an outlet port, said chamber defined by a pair of side walls, a top wall and a bottom wall, and an electrode element adapted to said chamber, said chamber having a substantially greater width than thickness, comprising:

• introducing a carrier medium from said inlet port into said chamber;
• introducing said matter into said inlet port;
• introducing a transport fluid into said inlet port and directing said transport fluid from said inlet port to said outlet port, such that said transport fluid travels through said chamber according to a velocity profile;
• applying a programmed voltage signal to said electrode element to create a spatially inhomogeneous electric field which causes a dielectrophoretic force on said matter having components normal to the direction of said transport fluid traveling through said chamber;
• and
• controlling said spatially inhomogeneous electric field to balance said dielectrophoretic force with a gravitational force on said matter to displace said matter to positions within said velocity profile in said transport fluid to discriminate said matter.

A method of discriminating matter utilizing dielectrophoresis and field flow fractionation in a chamber defined by a pair of side walls, a top wall, and a bottom wall, said method comprising:

• introducing a carrier medium including said matter into an inlet port of said chamber and directing said carrier medium from said inlet port toward top and bottom outlet ports coupled to said top and bottom walls, respectively;
• applying an electrical signal to an electrode element coupled to said chamber to create a spatially inhomogeneous electric field to generate a dielectrophoretic force on said matter having components normal to the direction of said carrier medium traveling through said chamber;
• controlling said spatially inhomogeneous electric field to balance said dielectrophoretic force with a gravitational force on said matter to displace said matter to different heights within said chamber to discriminate said matter;
• withdrawing a first portion of said carrier medium from said top outlet port;
• and
• withdrawing a second portion of said carrier medium from said bottom outlet port.

A method of discriminating matter utilizing dielectrophoresis and field flow fractionation in a chamber defined by a pair of side walls, a top wall, and a bottom wall, said method comprising:

• introducing a carrier medium including said matter into an inlet port of said chamber and directing said carrier medium from said inlet port toward top and bottom outlet ports coupled to said top and bottom walls, respectively;
• applying an electrical signal to an electrode element coupled to said chamber to create a spatially inhomogeneous electric field to generate a dielectrophoretic force on said matter having components normal to the direction of said carrier medium;
• controlling said spatially inhomogeneous electric field to balance said dielectrophoretic force with a gravitational force on said matter to displace said matter to different heights within said chamber to discriminate said matter;
• withdrawing a first portion of said carrier medium from said top outlet port at a first fluid flow rate;
• and
• withdrawing a second portion of said carrier medium from said bottom outlet port at a second fluid flow rate.

An apparatus for discriminating matter, comprising:

• a chamber defined by a top and bottom wall;
• an outlet port coupled to said chamber;
• an inlet port coupled to said chamber and in spaced relation with outlet port;
• an electrode element coupled to said chamber and configured to create a spatially inhomogeneous electric field to generate a dielectrophoretic force on said matter;
• and
• two or more sensing electrode elements coupled to said chamber and defining a detector integral with said chamber.