Methods and apparatus for detection and/or identification of analytes including bacteria using dielectrophoresis and electroosmotic traps. Switching between different frequencies of an applied electric field results in movement of the analyte between dieiectrophoresis and electroosmotic trapping states. The use of edge-based sensing techniques enables the use of electrodes with a larger form factor than nanowire sensors. Signal modulation based on analyte contact with the electrode edge is also described.

A method for performing contactless ODEP for separation of CTCs is provided with the steps of obtaining patients' blood with rare cell suspected CTCs; adding at least one fluorescent antibody binding to CTCs into the blood; staining the blood; injecting the stained blood with fluorescent dye into an ODEP device and then performing fluorescent image identification; trapping the CTCs with at least one fluorescent antibody in the ODEP device by creating an image pattern and then generating an ODEP force; Separating the trapped CTCs from other non-CTCs cells; absorbing the trapped CTCs; and obtaining a high purity of CTCs. An apparatus for performing contactless ODEP for separation of CTCs is also provided.

Sub-micrometer bioparticles are separated by size in a microfluidic channel utilizing a ratchet migration mechanism. A structure within the microfluidic channel includes an array of micro-posts arranged in laterally shifted rows. Reservoirs are disposed at each end of the microfluidic channel. A biased AC potential is applied across the channel via electrodes immersed into fluid in each of the reservoirs to induce a non-uniform electric field through the microfluidic channel. The applied potential comprises a first waveform with a first frequency that induces electro-kinetic flow of sub-micrometer bioparticles in the microfluidic channel, and an intermittent superimposed second waveform with a higher frequency. The second waveform selectively induces a dielectrophoretic trapping force to selectively impart ratchet migration based on particle size for separating the sub-micrometer bioparticles by size in the microfluidic channel.

An apparatus and method for isolating bacterial particles in a sample using a container with material in temporary fluid blocking position to lower orifice in the container, a separation medium having an electrical conductivity lower than and physical density greater than that of the sample above the material that supports a sample concentrate after passing through the separation medium when exposed to centrifugal force, a heating element for liquefying the material to permit flow into a chamber past an electrode array that attracts and holds subject particles. The system allows rapid detection and isolation of particles from samples from animal, human, environmental sites, a bio-industrial reactor or a food or beverage production facility requiring relatively small volumes, short incubation times resulting in structurally intact particles for further analysis. Testing may be completed in a single unit that requires decreased technician manipulation, fewer steps and a decrease in cross-contamination.

Microfluidic devices in which electrokinetic mechanisms move droplets of a liquid or particles in a liquid are described. The devices include at least one electrode that is optically transparent and/or flexible.

A photoelectrical device for detection of bacterial cell density includes a substrate, a driving electrode layer, an AC power source and a photoelectric conversion layer. The driving electrode layer is disposed on the substrate and includes a central electrode and a peripheral electrode pattern surrounding the central electrode. A fluid sample is disposed on the driving electrode layer. The AC power source is electrically connected to the driving electrode layer, and used to produce a non-uniform alternating electric field in the fluid sample on the driving electrode layer for driving the target bioparticles to gather up on the central electrode to form a particle cluster. The photoelectric conversion layer is used for receiving a light detecting beam after passing through the particle cluster and outputting an electric current based on the optical density of light detecting beam. The electric current changes as a concentration of the target bioparticles changes.

A photoelectrical device for detection of bacterial cell density includes a substrate, a driving electrode layer, an AC power source and a photoelectric conversion layer. The driving electrode layer is disposed on the substrate and includes a central electrode and a peripheral electrode pattern surrounding the central electrode. A fluid sample is disposed on the driving electrode layer. The AC power source is electrically connected to the driving electrode layer, and used to produce a non-uniform alternating electric field in the fluid sample on the driving electrode layer for driving the target bioparticles to gather up on the central electrode to form a particle cluster. The photoelectric conversion layer is used for receiving a light detecting beam after passing through the particle cluster and outputting an electric current based on the optical density of light detecting beam. The electric current changes as a concentration of the target bioparticles changes.

A synthetic bead for use in mineral separation is described. The synthetic bead has a surface made of a synthetic material such as polymer and the synthetic material is functionalized with molecules having a functional group for attaching mineral particles to the surface in a separation process. The synthetic beads can be placed in flotation cell containing a mixture of water, valuable material and unwanted material or in a pipeline where the mixture is transported from one location to another. The enriched synthetic beads carrying the mineral particles are separated from the unwanted materials in the mixture. The mineral particles are then released from the synthetic beads by means of low pH treatment, ultrasonic agitation, thermal or electromagnetic treatment.

A synthetic bead for use in mineral separation is described. The synthetic bead has a surface made of a synthetic material such as polymer and the synthetic material is functionalized with molecules having a functional group for attaching mineral particles to the surface in a separation process. The synthetic beads can be placed in flotation cell containing a mixture of water, valuable material and unwanted material or in a pipeline where the mixture is transported from one location to another. The enriched synthetic beads carrying the mineral particles are separated from the unwanted materials in the mixture. The mineral particles are then released from the synthetic beads by means of low pH treatment, ultrasonic agitation, thermal or electromagnetic treatment.

The invention generally relates to assemblies for displacing droplets from a vessel that facilitate the collection and transfer of the droplets while minimizing sample loss. In certain aspects, the assembly includes at least one droplet formation module, in which the module is configured to form droplets surrounded by an immiscible fluid. The assembly also includes at least one chamber including an outlet, in which the chamber is configured to receive droplets and an immiscible fluid, and in which the outlet is configured to receive substantially only droplets. The assembly further includes a channel, configured such that the droplet formation module and the chamber are in fluid communication with each other via the channel. In other aspects, the assembly includes a plurality of hollow members, in which the hollow members are channels and in which the members are configured to interact with a vessel. The plurality of hollow members includes a first member configured to expel a fluid immiscible with droplets in the vessel and a second member configured to substantially only droplets from the vessel. The assembly also includes a main channel, in which the second member is in fluid communication with the main channel. The assembly also includes at least one analysis module connected to the main channel.