Abstract: Methods and systems are provided for serial femtosecond crystallography for reducing the vast amount of waste of injected crystals practiced with traditional continuous flow injections. A micrometer-scale 3-D printed water-in-oil droplet generator device includes an oil phase inlet channel, an aqueous phase inlet channel, a droplet flow outlet channel, and two embedded non-contact electrodes. The inlet and outlet channels are connected internally at a junction. The electrodes comprise gallium metal injected within the 3-D printed device. Voltage across the electrodes generates water-in-oil droplets, determines a rate for a series of droplets, or triggers a phase shift in the droplets. An external trigger generates the droplets based on the frequency of an XFEL utilized in droplet detection, thereby synchronizing a series of droplets with x-ray pulses for efficient crystal detection. The generated droplets can be coupled to an SFX with XFEL experiment compatible with common liquid injector such as a GDVN.

Abstract: A 3D printed hybrid nozzle device combining a microfluidic mixer with a liquid jet injector that addresses the bottleneck of investigating substrate-initiated biological reaction paths employing serial crystallography with XFELs. The hybrid nozzle provides for injecting aqueous protein crystal jets after fast mixing (<5 ms), reaching reaction time points (e.g., about 10 ms to about 150 ms) suitable to resolve enzyme kinetics.

Abstract: Methods and systems are described for tuning an electrical field gradient for insulator-based di electrophoresis (iDEP). A fluidic layer defines a fluidic channel adjacent to a substrate. A deformable membrane is positioned adjacent to the fluidic channel. An actuator controllably causes the deformable membrane to deflect into the fluidic channel restricting a fluidic flow in the fluidic channel. A control system is configured to tune an electrical field gradient by operating the actuator to adjust a magnitude of the deflection of the deformable membrane into the fluidic channel.

Abstract: 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.

Abstract: A 3D printed hybrid nozzle device combining a microfluidic mixer with a liquid jet injector that addresses the bottleneck of investigating substrate-initiated biological reaction paths employing serial crystallography with XFELs. The hybrid nozzle provides for injecting aqueous protein crystal jets after fast mixing (<5 ms), reaching reaction time points (e.g., about 10 ms to about 150 ms) suitable to resolve enzyme kinetics.

Abstract: A microfluidic apparatus, systems and methods for microfluidic crystallization based on gradient mixing. In one embodiment, the apparatus includes (a) a first layer, (b) a plurality of first channels and a plurality of vacuum chambers both arranged in the first layer, where the plurality of vacuum chambers are each coupled to at least one of the first channels, (c) a membrane having first and second surfaces, where the first surface of the membrane is coupled to the first layer, (d) a second layer coupled to the second surface of the membrane, (e) a plurality of wells and a plurality of second channels both arranged in the second layer, where the wells are each coupled to at least one of the plurality of second channels and (f) a plurality of barrier walls each disposed in the plurality of second channels and arranged opposite to one of the plurality of vacuum chambers.

Abstract: A microfluidic apparatus, systems and methods for microfluidic crystallization based on gradient mixing. In one embodiment, the apparatus includes (a) a first layer, (b) a plurality of first channels and a plurality of vacuum chambers both arranged in the first layer, where the plurality of vacuum chambers are each coupled to at least one of the first channels, (c) a membrane having first and second surfaces, where the first surface of the membrane is coupled to the first layer, (d) a second layer coupled to the second surface of the membrane, (e) a plurality of wells and a plurality of second channels both arranged in the second layer, where the wells are each coupled to at least one of the plurality of second channels and (f) a plurality of barrier walls each disposed in the plurality of second channels and arranged opposite to one of the plurality of vacuum chambers.

Abstract: A microfluidic apparatus, systems and methods for microfluidic crystallization based on gradient mixing. In one embodiment, the apparatus includes (a) a first layer, (b) a plurality of first channels and a plurality of vacuum chambers both arranged in the first layer, where the plurality of vacuum chambers are each coupled to at least one of the first channels, (c) a membrane having first and second surfaces, where the first surface of the membrane is coupled to the first layer, (d) a second layer coupled to the second surface of the membrane, (e) a plurality of wells and a plurality of second channels both arranged in the second layer, where the wells are each coupled to at least one of the plurality of second channels and (f) a plurality of barrier walls each disposed in the plurality of second channels and arranged opposite to one of the plurality of vacuum chambers.

Abstract: A microfluidic device for size-based particle separation and methods for its use, where the microfluidic device comprises: (a) an inlet reservoir, where the inlet reservoir is configured for communication with an inlet electrode, (b) an insulator constriction coupled to the inlet reservoir via a microchannel, where the insulator constriction comprises an insulating material, and (c) a plurality of outlet channels each defining a first end and a second end, where the first end of each of the plurality of outlet channels is coupled to the insulator constriction, where the second end of each of the plurality of outlet channels is coupled to one of a plurality of outlet reservoirs, and where the plurality of outlet reservoirs are configured for communication with one or more outlet electrodes.

Abstract: A microfluidic device for size-based particle separation and methods for its use, where the microfluidic device comprises: (a) an inlet reservoir, where the inlet reservoir is configured for communication with an inlet electrode, (b) an insulator constriction coupled to the inlet reservoir via a microchannel, where the insulator constriction comprises an insulating material, and (c) a plurality of outlet channels each defining a first end and a second end, where the first end of each of the plurality of outlet channels is coupled to the insulator constriction, where the second end of each of the plurality of outlet channels is coupled to one of a plurality of outlet reservoirs, and where the plurality of outlet reservoirs are configured for communication with one or more outlet electrodes.

Abstract: A device, method and kit for the electrophoretic separation and purification of charged and neutral compounds in an analyte solution. The device comprises a chamber (1), at least one wall of which is composed of a chemical buffering system (4). A potential difference is applied across the buffering system, resulting in the charged and neutral compounds being differentially separated by extraction of the charged compounds into the buffering system. The device also comprises means for collecting the separated compounds, preferably in ampholyte-free or buffer-free solution and optionally means for recycling the separated fractions.

Abstract: A device, method and kit for the electrophoretic separation and purification of charged and neutral compounds in an analyte solution. The device comprises a chamber (1), at least one wall of which is composed of a chemical buffering system (4). A potential difference is applied across the buffering system, resulting in the charged and neutral compounds being differentially separated by extraction of the charged compounds into. the buffering system. The device also comprises means for collecting the separated compounds, preferably in ampholyte-free or buffer-free solution and optionally means for recycling the separated fractions.