Abstract: An apparatus for simultaneously aligning and interconnecting microfluidic ports is presented. Such interconnections are required to utilize microfluidic devices fabricated in Micro-Electromechanical-Systems (MEMS) technologies, that have multiple fluidic access ports (e.g. 100 micron diameter) within a small footprint, (e.g. 3 mm×6 mm). Fanout of the small ports of a microfluidic device to a larger diameter (e.g. 500 microns) facilitates packaging and interconnection of the microfluidic device to printed wiring boards, electronics packages, fluidic manifolds etc.

Abstract: A surface-micromachined fluid-ejection apparatus is disclosed which utilizes a piston to provide for the ejection of jets or drops of a fluid (e.g. for ink-jet printing). The piston, which is located at least partially inside a fluid reservoir, is moveable into a cylindrical fluid-ejection chamber connected to the reservoir by a microelectromechanical (MEM) actuator which is located outside the reservoir. In this way, the reservoir and fluid-ejection chamber can be maintained as electric-field-free regions thereby allowing the apparatus to be used with fluids that are electrically conductive or which may react or break down in the presence of a high electric field. The MEM actuator can comprise either an electrostatic actuator or a thermal actuator.

Abstract: A new architecture for packaging surface micromachined electro-microfluidic devices is presented. This architecture relies on two scales of packaging to bring fluid to the device scale (picoliters) from the macro-scale (microliters). The architecture emulates and utilizes electronics packaging technology. The larger package consists of a circuit board with embedded fluidic channels and standard fluidic connectors (e.g. Fluidic Printed Wiring Board). The embedded channels connect to the smaller package, an Electro-Microfluidic Dual-Inline-Package (EMDIP) that takes fluid to the microfluidic integrated circuit (MIC). The fluidic connection is made to the back of the MIC through Bosch-etched holes that take fluid to surface micromachined channels on the front of the MIC. Electrical connection is made to bond pads on the front of the MIC.

Abstract: Microfluidic devices are disclosed which can be manufactured using surface-micromachining. These devices utilize an electroosmotic force or an electromagnetic field to generate a flow of a fluid in a microchannel that is lined, at least in part, with silicon nitride. Additional electrodes can be provided within or about the microchannel for separating particular constituents in the fluid during the flow based on charge state or magnetic moment. The fluid can also be pressurized in the channel. The present invention has many different applications including electrokinetic pumping, chemical and biochemical analysis (e.g. based on electrophoresis or chromatography), conducting chemical reactions on a microscopic scale, and forming hydraulic actuators.

Abstract: An apparatus and method are disclosed for in vitro transformation of living cells. The apparatus, which is formed as a microelectromechanical device by surface micromachining, can be used to temporarily disrupt the cell walls or membrane of host cells one at a time so that a particular substance (e.g. a molecular tag, nucleic acid, bacteria, virus etc.) can be introduced into the cell. Disruption of the integrity of the host cells (i.e. poration) can be performed mechanically or electrically, or by both while the host cells are contained within a flow channel. Mechanical poration is possible using a moveable member which has a pointed or serrated edge and which is driven by an electrostatic actuator to abrade, impact or penetrate the host cell. Electroporation is produced by generating a relatively high electric field across the host cell when the host cell is located in the flow channel between a pair of electrodes having a voltage applied therebetween.

Abstract: A new architecture for packaging surface micromachined electro-microfluidic devices is presented. This architecture relies on two scales of packaging to bring fluid to the device scale (picoliters) from the macro-scale (microliters). The architecture emulates and utilizes electronics packaging technology. The larger package consists of a circuit board with embedded fluidic channels and standard fluidic connectors (e.g. Fluidic Printed Wiring Board). The embedded channels connect to the smaller package, an Electro-Microfluidic Dual-Inline-Package (EMDIP) that takes fluid to the microfluidic integrated circuit (MIC). The fluidic connection is made to the back of the MIC through Bosch-etched holes that take fluid to surface micromachined channels on the front of the MIC. Electrical connection is made to bond pads on the front of the MIC.

Abstract: Microfluidic devices are disclosed which can be manufactured using surface-micromachining. These devices utilize an electroosmotic force or an electromagnetic field to generate a flow of a fluid in a microchannel that is lined, at least in part, with silicon nitride. Additional electrodes can be provided within or about the microchannel for separating particular constituents in the fluid during the flow based on charge state or magnetic moment. The fluid can also be pressurized in the channel. The present invention has many different applications including electrokinetic pumping, chemical and biochemical analysis (e.g. based on electrophoresis or chromatography), conducting chemical reactions on a microscopic scale, and forming hydraulic actuators.

Abstract: Structures for use in conjunction with surface micromachined structures are formed using a two-step etching process. In various exemplary embodiments, the two-step etching process comprises a modified Bosch etch. According to various exemplary embodiments of the two-step etch, first mask and second masks are used to prepare a layer for etching one or more desired structures. The first mask is used to define at least one large feature. The second mask is used to define at least one small feature (small as compared to the at least one large feature). The second mask is formed over the first mask which is formed over the layer. In the first etching step, the at least one small feature is etched into the layer. Then, the second mask is removed using the chemical rinsing agent. In the second etching step, the at least one large feature is etched into the layer such that the at least one small feature propagates further into the layer ahead of the at least one large feature. The first mask is then removed.

Abstract: This invention provides microfabricated systems for extraction of desired particles from a sample stream containing desired and undesired particles. The sample stream is placed in laminar flow contact with an extraction stream under conditions in which inertial effects are negligible. The contact between the two streams is maintained for a sufficient period of time to allow differential transport of the desired particles from the sample stream into the extraction stream. In a preferred embodiment the differential transport mechanism is diffusion. The extraction system of this invention coupled to a microfabricated diffusion-based mixing device and/or sensing means allows picoliter quantities of fluid to be processed or analyzed on devices no larger than silicon wafers. Such diffusion-based mixing or sensing devices are preferably channel cell systems for detecting the presence and/or measuring the quantity of analyte particles in a sample stream.

Abstract: A new architecture for packaging surface micromachined electro-microfluidic devices is presented. This architecture relies on two scales of packaging to bring fluid to the device scale (picoliters) from the macro-scale (microliters). The architecture emulates and utilizes electronics packaging technology. The larger package consists of a circuit board with embedded fluidic channels and standard fluidic connectors (e.g. Fluidic Printed Wiring Board). The embedded channels connect to the smaller package, an Electro-Microfluidic Dual-Inline-Package (EMDIP) that takes fluid to the microfluidic integrated circuit (MIC). The fluidic connection is made to the back of the MIC through Bosch-etched holes that take fluid to surface micromachined channels on the front of the MIC. Electrical connection is made to bond pads on the front of the MIC.

Abstract: An electronic drive system applies a drive signal to an electrostatically actuated device such that a resulting electric field has a constant force. In various exemplary embodiments, the electronic drive system applies a drive signal to an electrostatically actuated fluid ejector that has a piston and a faceplate including a nozzle hole. A dielectric fluid to be ejected is supplied between the piston and the faceplate. The drive signal is applied to one of the piston and the faceplate. The drive signal generates an electric field across the fluid between the piston and the faceplate. The electric field causes the piston to be electrostatically attracted towards the faceplate so that a jet or drop of fluid is ejected through the nozzle hole of the faceplate. According to exemplary embodiments, the drive signal is from a constant current source or is reduced over the course of its lifetime.

Abstract: A piston structure is movably mounted within a fluid chamber. Movement of the piston structure towards a faceplate causes a portion of the fluid between the piston and the faceplate to be forced out of the nozzle hole in the faceplate, forming a drop or jet of the fluid. Viscous forces that are generated by the flow of fluid along a working surface of the piston structure toward and away from the nozzle hole generate a force that resists the movement of the piston structure. This resistance force tends to slow the piston motion, and prevents the piston from contacting the faceplate. In various embodiments, the fluid chamber is defined by a cylinder structure. The piston structure moves within the cylinder structure. The cylinder structure and the faceplate define the fluid chamber. The cylinder structure and the piston structure are designed to cooperate so that the movement of the piston structure within the cylinder structure ejects fluid according to various design criteria.

Abstract: A bi-directional fluid ejector according to the systems and methods of this invention operates on the principle of electrostatic attraction. In various exemplary embodiments, the fluid ejector includes a sealed dual diaphragm arrangement, an electrode arrangement that is parallel and opposite to the sealed diaphragms, and a structure which contains the fluid to be ejected. A diaphragm chamber containing a relatively incompressible fluid is situated behind, and is sealed by, the diaphragms. At least one nozzle hole is formed in a faceplate of the ejector over one of the diaphragms. A drive signal is applied to at least one electrode of the electrode arrangement to generate an electrostatic field between the electrode and a first one of the diaphragms. The first diaphragm is attracted towards the electrode by an electrostatic force into a deformed shape due to the electrostatic field. Upon deforming, pressure is transmitted to a second one of the sealed diaphragms.

Abstract: A fluid ejection system according to this invention operates on the principle of electrostatic or magnetic attraction. In various exemplary embodiments, the fluid ejection system includes a sealed diaphragm arrangement having at least one diaphragm portion and a diaphragm chamber defined at least partially by the at least one diaphragm portion, a nozzle hole located over the at least one diaphragm portion, an ejection chamber defined between the nozzle hole and the least one diaphragm portion and a secondary dielectric fluid reservoir containing a secondary dielectric fluid. The ejection chamber receives a primary fluid to be ejected. The secondary dielectric fluid reservoir is in fluid communication with the diaphragm chamber to supply the secondary dielectric fluid to the diaphragm chamber. In various exemplary embodiments, the secondary dielectric fluid is a liquid, a substantially incompressible fluid, and/or a high performance dielectric fluid having a dielectric constant greater than 1.

Abstract: An electrostatic microelectromechanical system (MEMS) based fluid ejector comprises a movable piston structure and a stationary faceplate. A fluid chamber is defined between the piston structure and a substrate. The piston structure 110 may be resiliently mounted on the substrate by one or more spring elements. A fluid to be ejected is supplied in the fluid chamber from a fluid reservoir through a fluid refill hole formed in the substrate. The faceplate includes a nozzle hole through which a fluid jet or drop is ejected. In various exemplary embodiments, the piston structure moves towards the faceplate by electrostatic attraction between the piston structure and the faceplate. As a result of the movement of the piston structure, a portion of the fluid between the piston structure and the faceplate is forced out of the nozzle hole, forming a jet or drop of the fluid.

Abstract: The systems and methods of the present invention operate by magnetically driving a fluid ejector. In various exemplary embodiments, a primary coil and a secondary coil are situated in the ejector. The ejector has a movable piston usable to eject fluid through a nozzle hole. The piston may be resiliently mounted and biased to an at-rest position. A drive signal is applied to cause current to flow in the primary coil. The current flow generates a magnetic field that induces a current in the secondary coil. Either the primary coil or the secondary coil or associated with the piston and the other is associated with a fixed structure of the ejector. As a result, a magnetic force is generated that pushes the piston either toward a faceplate so that a drop of fluid is ejected through the nozzle hole in the faceplate or away from the faceplate so that fluid fills in a fluid chamber between the piston and the faceplate.

Abstract: A method and apparatus including programmed computers are provided for determining the viscosity of a first stream in a laminar flow and a second stream in a laminar flow, the flow rates, the centerline of the flow channel, and the position of the interface between the streams with respect to the centerline, and for calculating viscosity ratio of the first stream to the second.

Abstract: Methods and apparatuses including programmed computers are provided for determining the initial concentration of diffusible particles in a sample stream introduced into a system wherein the sample stream which contains the diffusible particles flows in adjacent laminar flow with an indicator stream containing an indicator substance capable of exhibiting an observable change at a known concentration of the diffusible particles.

Abstract: This invention provides a microfabricated extraction system and methods for extracting desired particles from a sample stream containing desired and undesired particles. The sample stream is placed in laminar flow contact with an extraction stream under conditions in which inertial effects are negligible. The contact between the two streams is maintained for a sufficient period of time to allow differential transport of the desired particles from the sample stream into the extraction stream. In a preferred embodiment the differential transport mechanism is diffusion. The extraction system of this invention coupled to a microfabricated diffusion-based mixing device and/or sensing device allows picoliter quantities of fluid to be processed or analyzed on devices no larger than silicon wafers.