A target substance detection method includes forming a complex by causing a target substance and a dielectric particle to bind to each other, the dielectric particle being modified with a substance having a property of specifically binding to the target substance; separating the complex and an unbound particle from each other in a liquid by dielectrophoresis, the unbound particle being a dielectric particle not constituting the complex; and detecting the target substance included in the separated complex by using an imaging element.

A target substance detection method includes forming a complex by causing a target substance and a dielectric particle to bind to each other, the dielectric particle being modified with a substance (for example, an antibody) having a property of specifically binding to the target substance; subjecting a bound particle and an unbound particle to dielectrophoresis in a liquid, the bound particle being the dielectric particle constituting the complex, the unbound particle being a dielectric particle not constituting the complex; and detecting the target substance in the complex, based on a difference in motion between the bound particle and the unbound particle caused by the dielectrophoresis.

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.

The present invention relates to the field of microfluidics and in particular to devices and methods for sorting objects in microfluidic channels. These devices and methods allow for fast and robust sorting in two-way and multi-way setups. They also enable sorting over extended periods of time.

Microfluidic devices having a circuit substrate with a control unit, a switching mechanism associated with a dielectrophoresis (DEP) electrode, and a memory unit are described. Switching instructions may be received, stored, and retrieved by the control unit and used to control the DEP electrode via the switching mechanism. Systems comprising the described microfluidic devices and methods of controlling the described microfluidic devices are included herein.

A print agent filtration apparatus is disclosed. The filtration apparatus is to remove non-liquid contaminant from liquid carrier. The apparatus comprises an electrode having a first surface, wherein the electrode is to generate an electric field towards liquid carrier containing non-liquid contaminant. The apparatus further comprises a second surface to accumulate non-liquid contaminant removed from the liquid carrier, the second surface being formed at least in part from a ceramic and movable relative to the first surface. A gap between the first surface and the second surface is substantially constant over the extent of the first surface. The first surface and the second surface define a passage therebetween through which the liquid carrier may pass. An electric field formed between the first surface and the second surface is to act on the liquid carrier, to thereby cause non-liquid contaminant to adhere to the second surface. A method and a print apparatus are also disclosed.

A novel Self-Locking Optoelectronic Tweezers (SLOT) for single microparticle manipulation across a large area is provided. DEP forces generated from ring-shape lateral phototransistors are utilized for locking single microparticles or cells in the dark state. The locked microparticles or cells can be selectively released by optically deactivating these locking sites.

The invention relates to a method for operating a fluidic microsystem (100) for the dielectrophoretic manipulation of suspended particles (1) having a particle diameter in a suspension liquid (2), wherein the microsystem (100) comprises: —a channel (10) having a longitudinal direction; —an electrode device (20) having an electrode (21), the longitudinal extent of which deviates from the longitudinal direction of the channel (10) and which has individually controllable electrode segments (22) for producing dielectrophoretic forces which act on the particles (1), each electrode segment (22) having a deflection angle α, relative to the longitudinal direction of the channel (10), and a segment length (s.sub.i), which determine a segment offset (D.sub.i) perpendicular to the longitudinal direction of the channel (10); and—a control device (30). The method comprises: —producing a flow of the suspension liquid (2) with a flow velocity so that the particles (1) successively pass through an interaction region of the electrode (21), which interaction region is spanned by the electrode segments (22); and—activating the electrode segments (22) in order to deflect the particles (1) onto predetermined motion paths (4, 5), which are determined by a superposition of flow forces in the flow of the suspension liquid (2) and of the dielectrophoretic forces at the electrode segments (22). During the passage of each particle, each of the electrode segments (22) which are passed by the particle (1) is activated in a clocked manner for a predetermined activation duration, according to the desired motion path (4, 5), the activation duration of each electrode segment (22) being determined by the quotient of the segment length (s.sub.i) of the electrode segment (22) and the flow velocity. The electrode segments (22) are dimensioned such that the segment offset (D.sub.i) of each electrode segment (22) is less than the particle diameter. For the deflection of each particle (1), at least two successive electrode segments (22) cooperate.

A nanocarbon separation device includes a separation tank that is configured to accommodate a dispersion liquid including nanocarbons, a first electrode provided at an upper part in the separation tank, a second electrode provided at a lower part in the separation tank, an evaluation unit that is configured to evaluate a physical state or a chemical state of the dispersion liquid, and a determination unit that is configured to determine a separation state between metallic nanocarbons and semiconducting nanocarbons included in the dispersion liquid from the physical state or the chemical state.

Systems, methods, and devices are described herein for identifying, monitoring, isolating, or selecting a cell having a predefined characteristic in a mixed population of cells utilizing a combination of any one or more of iDEP, a region of localized field enhancement, a variable frequency electric field, a wide bandwidth amplifier, and/or an imaging apparatus.