Abstract: A microfabricated sheath flow structure for producing a sheath flow includes a primary sheath flow channel for conveying a sheath fluid, a sample inlet for injecting a sample into the sheath fluid in the primary sheath flow channel, a primary focusing region for focusing the sample within the sheath fluid and a secondary focusing region for providing additional focusing of the sample within the sheath fluid. The secondary focusing region may be formed by a flow channel intersecting the primary sheath flow channel to inject additional sheath fluid into the primary sheath flow channel from a selected direction. A sheath flow system may comprise a plurality of sheath flow structures operating in parallel on a microfluidic chip.

Abstract: A microfluidic device for separating a sample by chromatography includes diffusion bonded metallic sheets joined together to create a hermetically sealed interface between each adjacent metallic sheet without the introduction of a secondary material. Enclosed within the diffusion bonded sheets is a separation channel accessible by at least one of an inlet or an outlet. The separation channel is packed with micrometer-sized particles serving as a stationary phase in a chromatographic separation. Wetted surfaces of the separation channel include a coating of an organic material at least one monolayer thick.

Abstract: Described are techniques for use in connection with analyzing a droplet. One or more droplets of a sample are formed on a surface of a digital microfluidic device. The droplets are manipulated to perform processing using said one or more droplets generating one or more resulting droplets. The one or more resulting droplets may be transferred from the microfluidic device to another device for analysis. The one or more droplets may also be provided to the digital microfluidic device from yet another device or analysis instrument.

Abstract: A microfabricated sheath flow structure for producing a sheath flow includes a primary sheath flow channel for conveying a sheath fluid, a sample inlet for injecting a sample into the sheath fluid in the primary sheath flow channel, a primary focusing region for focusing the sample within the sheath fluid and a secondary focusing region for providing additional focusing of the sample within the sheath fluid. The secondary focusing region may be formed by a flow channel intersecting the primary sheath flow channel to inject additional sheath fluid into the primary sheath flow channel from a selected direction. A sheath flow system may comprise a plurality of sheath flow structures operating in parallel on a microfluidic chip.

Abstract: A microfluidic device for separating a sample by chromatography includes diffusion bonded metallic sheets joined together to create a hermetically sealed interface between each adjacent metallic sheet without the introduction of a secondary material. Enclosed within the diffusion bonded sheets is a separation channel accessible by at least one of an inlet or an outlet. The separation channel is packed with micrometer-sized particles serving as a stationary phase in a chromatographic separation. Wetted surfaces of the separation channel include a coating of an organic material at least one monolayer thick.

Abstract: Flow through pressure sensors for use in fluid chromatography systems include a planar device formed from diffusion bonding of a plurality of metallic sheets and at least one sensing element. The planar device has a top surface, a bottom surface and a flow through channel. A diaphragm formed from a portion of one of the top or bottom surfaces is located adjacent to a sensing region of the flow through channel and is attached to the sensing element. The diaphragm is sized to deflect a distance in response to fluid pressure in the sensing region, which has an internal volume of less than about 25 microliters. The diaphragm and attached sensing element form a pressure sensor that measures strain or deflection of the diaphragm to calculate a pressure within the sensing region.

Abstract: An improved actuator for use in a microfluidic particle sorting system utilizes a staggered packing scheme for a plurality of actuators used to selectively deflect a particle in an associated sorting channel from a stream of channels. An actuator block may be provided for housing a two-dimensional array of actuators, each configured to align with an actuation port in an associated sorting chip containing a plurality of sorting channels. The actuator block may include a built-in stressing means to pre-stress each actuator housed by the block. An actuator comprising a piezo-electric stack may employ contact-based electrical connection rather than soldered wires to improve packing density. The actuator may be an external actuator. That is, the external actuator is external to the substrate in which the sorting channels are formed.

Abstract: Provided are systems and methods for adapting to volume variations in microfluidic chromatography columns. A column is calibrated by comparing a parameter of the column with a same parameter of a reference column and generating, by a processor, an adjustment factor in response to the comparison between the parameter of the column with a same parameter of the reference column. Volume differences between the calibrated column and the reference column are compensated for by integrating the generated adjustment factor into a sample separation involving the calibrated column.

Abstract: Flow through pressure sensors for use in fluid chromatography systems include a planar device formed from diffusion bonding of a plurality of metallic sheets and at least one sensing element. The planar device has a top surface, a bottom surface and a flow through channel. A diaphragm formed from a portion of one of the top or bottom surfaces is located adjacent to a sensing region of the flow through channel and is attached to the sensing element. The diaphragm is sized to deflect a distance in response to fluid pressure in the sensing region, which has an internal volume of less than about 25 microliters. The diaphragm and attached sensing element form a pressure sensor that measures strain or deflection of the diaphragm to calculate a pressure within the sensing region.

Abstract: A system that incorporates teachings of the subject disclosure may include, for example, a process that includes obtaining a porous medium comprising a porous material having a first shape and an initial porosity profile. The porous medium is engaged with a cavity in a fluidic device, wherein the cavity is in fluid communication with a channel of the fluidic device. The first shape of the porous material can be adjusted to a second shape resulting in the initial porosity profile being adjusted to a target porosity profile. Such adjustment can be accomplished by the engaging of the porous medium with the cavity, by pre-adjusting a shape of the porous media before insertion into the cavity, or by some combination thereof. Other embodiments are disclosed.

Abstract: An improved actuator for use in a microfluidic particle sorting system utilizes a staggered packing scheme for a plurality of actuators used to selectively deflect a particle in an associated sorting channel from a stream of channels. An actuator block may be provided for housing a two-dimensional array of actuators, each configured to align with an actuation port in an associated sorting chip containing a plurality of sorting channels. The actuator block may include a built-in stressing means to pre-stress each actuator housed by the block. An actuator comprising a piezo-electric stack may employ contact-based electrical connection rather than soldered wires to improve packing density. The actuator may be an external actuator. That is, the external actuator is external to the substrate in which the sorting channels are formed.

Abstract: A method for switching a high pressure fluid includes applying a fixed force between a planar surface of a rotor and a planar surface of a stator. The planar surface of the rotor includes a fluidic channel and the planar surface of the stator has a pair of ports to receive and provide the fluid. A control signal is applied to a linear actuator coupled to the rotor to generate a controllable force between the planar surfaces of the rotor and stator. The control signal is responsive to a rotational state of the rotor. The total force between the planar surfaces of the rotor and the stator is substantially equal to a sum of the fixed force and the controllable force. The method reduces the wear and extends the lifetime of components in a rotary shear seal valve.

Abstract: An improved actuator for use in a microfluidic particle sorting system utilizes a staggered packing scheme for a plurality of actuators used to selectively deflect a particle in an associated sorting channel from a stream of channels. An actuator block may be provided for housing a two-dimensional array of actuators, each configured to align with an actuation port in an associated sorting chip containing a plurality of sorting channels. The actuator block may include a built-in stressing means to pre-stress each actuator housed by the block. An actuator comprising a piezo-electric stack may employ contact-based electrical connection rather than soldered wires to improve packing density. The actuator may be an external actuator. That is, the external actuator is external to the substrate in which the sorting channels are formed.

Abstract: A system (e.g., a chromatography system) includes a rotor, a microfluidic device, a rotor driver, a clamping mechanism, and control electronics. The rotor defines a plurality of first fluid-conveying features. The micro fluidic device defines one or more channels and a plurality of second fluid-conveying features, in fluid communication with the one or more channels. The rotor driver is coupled to the rotor and is configured to rotate the rotor, relative to the microfluidic device, between a first position and a second position such that, in each of the positions, at least one of the first fluid-conveying features cooperates with at least one of the one or more channels to provide for fluid communication therebetween. The clamping mechanism is operable to provide a sealing force to establish a fluid-tight seal between the rotor and the microfluidic device.

Abstract: An improved actuator for use in a microfluidic particle sorting system utilizes a staggered packing scheme for a plurality of actuators used to selectively deflect a particle in an associated sorting channel from a stream of channels. An actuator block may be provided for housing a two-dimensional array of actuators, each configured to align with an actuation port in an associated sorting chip containing a plurality of sorting channels. The actuator block may include a built-in stressing means to pre-stress each actuator housed by the block. An actuator comprising a piezo-electric stack may employ contact-based electrical connection rather than soldered wires to improve packing density. The actuator may be an external actuator. That is, the external actuator is external to the substrate in which the sorting channels are formed.

Abstract: A planar microfluidic chemical separation device includes a separation channel that is located in the plane of the device. The device also includes one or more vias situated perpendicular to the separation channel. The vias extends between the separation channel and an outer surface of the substrate for fluid communication with the separation channel. The vias have cross-sectional areas that are substantially less than a cross-sectional area of a first region of the separation channel to inhibit band-broadening caused by passage of a sample band through the one or more vias.

Abstract: Described are a rotary shear seal valve and a method for switching a high pressure fluid. The method includes applying a fixed force between a planar surface of a rotor and a planar surface of a stator. The planar surface of the rotor includes a fluidic channel and the planar surface of the stator has a pair of ports to receive and provide the fluid. A control signal is applied to a linear actuator coupled to the rotor to generate a controllable force between the planar surfaces of the rotor and stator. The control signal is responsive to a rotational state of the rotor. The total force between the planar surfaces of the rotor and the stator is substantially equal to a sum of the fixed force and the controllable force. The method reduces the wear and extends the lifetime of components in a rotary shear seal valve.

Abstract: A microfabricated sheath flow structure for producing a sheath flow includes a primary sheath flow channel for conveying a sheath fluid, a sample inlet for injecting a sample into the sheath fluid in the primary sheath flow channel, a primary focusing region for focusing the sample within the sheath fluid and a secondary focusing region for providing additional focusing of the sample within the sheath fluid. The secondary focusing region may be formed by a flow channel intersecting the primary sheath flow channel to inject additional sheath fluid into the primary sheath flow channel from a selected direction. A sheath flow system may comprise a plurality of sheath flow structures operating in parallel on a microfluidic chip.

Abstract: A microfabricated sheath flow structure for producing a sheath flow includes a primary sheath flow channel for conveying a sheath fluid, a sample inlet for injecting a sample into the sheath fluid in the primary sheath flow channel, a primary focusing region for focusing the sample within the sheath fluid and a secondary focusing region for providing additional focusing of the sample within the sheath fluid. The secondary focusing region may be formed by a flow channel intersecting the primary sheath flow channel to inject additional sheath fluid into the primary sheath flow channel from a selected direction. A sheath flow system may comprise a plurality of sheath flow structures operating in parallel on a microfluidic chip.

Abstract: Flow through pressure sensors for use in fluid chromatography systems include a planar device formed from diffusion bonding of a plurality of metallic sheets and at least one sensing element. The planar device has a top surface, a bottom surface and a flow through channel. A diaphragm formed from a portion of one of the top or bottom surfaces is located adjacent to a sensing region of the flow through channel and is attached to the sensing element. The diaphragm is sized to deflect a distance in response to fluid pressure in the sensing region, which has an internal volume of less than about 25 microliters. The diaphragm and attached sensing element form a pressure sensor that measures strain or deflection of the diaphragm to calculate a pressure within the sensing region.