Provided herein are systems and method for measuring cell stiffness. In particular, provided herein are microelectrode configuration and systems for measuring platelet deformation and stiffness.

A microfluidic apparatus for separating a droplet of an emulsion in a microfluidic environment is described. The microfluidic apparatus includes a flow cell comprising a first microfluidic channel configured for flowing a first fluid through the flow cell and a second microfluidic channel configured for flowing a stream of a second fluid through the flow cell. The microfluidic apparatus further comprises a first electrode positioned at the first microfluidic channel and a second electrode positioned at the second microfluidic channel on an opposite side of the interface with respect to the first electrode. The first electrode, the second electrode, and the first and second microfluidic channels are configured to generate a non-uniform electric field gradient in the microfluidic apparatus.

Method, apparatus, and computer program product for a microfluidic channel having a cover opposite its bottom and having electrodes with patterned two-dimensional conducting materials, such as graphene sheets integrated into the top of its bottom. Using the two-dimensional conducting materials, once a fluid sample is applied into the channel, highly localized modulated electric field distributions are generated inside the channel and the fluid sample. This generated field causes the inducing of dielectrophoretic (DEP) forces. These DEP forces are the same or greater than DEP forces that would result using metallic electrodes because of the sharp edges enabled by the two-dimension geometry of the two-dimensional conducting materials. Because of the induced forces, micro/nano-particles in the fluid sample are separated into particles that respond to a negative DEP force and particles that respond to a positive DEP. Microfluidic chips with microfluidic channels can be made using standard semiconductor manufacturing technology.

In various embodiments methods and devices are provided for focusing and/or sorting particles and/or cells in a microfluidic channel. In certain embodiments the device comprises a microfluidic channel comprising a plurality of electrodes disposed to provide dielectrophoretic (DEP) forces that are perpendicular to hydrodynamic flows along the channel; wherein said device is configured to apply voltages to said electrodes to provide an electric field minimum that is not centered in said microfluidic channel.

A method of driving an element of an active matrix electro-wetting on dielectric (AM-EWOD) device comprise applying a first alternating voltage to a reference electrode of the AM-EWOD device; and either (i) applying to the element electrode a second alternating voltage that has the same frequency as the first alternating voltage and that is out of phase with the first alternating voltage or (ii) holding the element electrode in a high impedance state. The effect of applying the second alternating voltage to the element electrode is to put the element in an actuated state in which the element is configured to actuate any liquid droplet present in the element, while the effect of holding the element electrode in the high impedance state is to put the element in a non-actuated state.

Described herein is a method of designing micro-fluidic devices. A target cost function based on device design parameters is chosen. The performance of one or more design candidates is run in a simulation model. A design candidate with a cost function closest to the target cost function is chosen and modified in an optimization routine to provide a modified design candidate having modified device design parameters. The cost function for the modified initial design candidate is computed, and when the modified design candidate has a computed cost function that meets the target cost function, optimized device design parameters of an optimized device design are obtained. Additional optimization iterations may be performed as needed to arrive at an optimized device design. A micro-fluidic device based on the optimized device design is manufactured.

Methods and apparatus for detecting, quantifying, enriching, and/or separating bacterial species in fluid sample are provided. The fluid sample is provided as input to a microfluidic passage of a microfluidic device, wherein the microfluidic device comprises at least one electrode disposed adjacent to the microfluidic passage. The at least one electrode is activated to capture bacteria in the sample using dielectrophoresis, wherein the capture efficiency of bacteria is at least 99%.

A microfluidic apparatus is provided having one or more sequestration pens configured to isolate one or more target micro-objects by changing the orientation of the microfluidic apparatus with respect to a globally active force, such as gravity. Methods of selectively directing the movements of micro-objects in such a microfluidic apparatus using gravitational forces are also provided. The micro-objects can be biological micro-objects, such as cells, or inanimate micro-objects, such as beads.

A method is provided for transporting a plurality of cells through a flow chamber, wherein the cells are initially immobilized on an internal surface of the flow chamber. The method comprises: selectively releasing the cells from the internal surface of the flow chamber; and flowing liquid through the flow chamber such that the released cells travel with the liquid, thereby transporting the cells through the flow chamber. Cells can be immobilized on or selectively released from the internal surface by applying or removing a trapping potential. The trapping potential can arise from an electric field gradient or an optical field gradient. Alternatively, cells can be selectively released from the surface using photocatalysis. Selective release allows cells to be individually observed or analyzed downstream, and can be based on a signal detected from one or more cells immobilized on the surface.

A apparatus for performing contactless ODEP for separation of CTCs comprises an ODEP device including a first conductive glass and a second conductive glass, the first conductive glass includes a transverse main channel and a longitudinal micro channel perpendicular to the main channel and joining the main channel at a cell separation zone; the first conductive glass includes a first hole and a second hole aligned with two ends of the main channel respectively, and a third hole aligned with one end of the micro channel that is distal to the cell separation zone; a sample receiving member disposed on and aligned with the first hole; an exhaust discharge member disposed on and aligned with the second hole; a target collection member disposed on and aligned with the third hole; and a controller including an optical projection device and an image fetch device.