Abstract: A field emission electron source and a method of manufacturing the same. A field emission electron source comprises an emitting electrode and an extractor gate electrode. The emitting electrode comprising a plurality of particles with nanosharp protrusions. The extractor gate electrode comprises a metal. The extractor gate electrode is formed in a same plane as the emitting electrode. The extractor gate electrode is formed surrounding the emitting electrode. A method of manufacturing a field emission electron source comprises forming an emitting electrode comprising a plurality of particles with nanosharp protrusions using a direct ink writing (DIW) printer. The method comprises forming an extractor gate electrode comprising a metal using the DIW printer.

Abstract: Techniques for manufacturing miniaturized diaphragm pumps using additive manufacturing techniques, such as polyjet printing, are provided, as are the pumps and systems that result from using such techniques to produce the pumps. The provided pumps include a compression chamber that has a first surface, a second opposed surface, and a conical outer wall that extends between the first surface and the second surface and that has a bowed configuration in which the outer wall has a generally concave shape. A diaphragm is disposed proximate to the compression chamber, and the pump also includes one or more valves that control the flow of fluid between the compression chamber and one more fluid ports. Fluid can be selectively vacuumed into and exhausted out of the compression chambers. Various manufacturing techniques for fabricating the pumps are also provided.

Abstract: A field emission electron source and a method of manufacturing the same. A field emission electron source comprises an emitting electrode and an extractor gate electrode. The emitting electrode comprising a plurality of particles with nanosharp protrusions. The extractor gate electrode comprises a metal. The extractor gate electrode is formed in a same plane as the emitting electrode. The extractor gate electrode is formed surrounding the emitting electrode. A method of manufacturing a field emission electron source comprises forming an emitting electrode comprising a plurality of particles with nanosharp protrusions using a direct ink writing (DIW) printer. The method comprises forming an extractor gate electrode comprising a metal using the DIW printer.

Abstract: Electrospray devices are described. The devices may comprise a substrate and a plurality of emitters. The emitters may comprise a plurality of channels therein, wherein the channels may be configured to convey immiscible liquids to the distal end of the emitters. The channels may be arranged such that, at the distal end, one liquid enclosed another liquid. The device may comprise a plurality of reservoirs, each reservoir being configured to contain liquid therein and to convey the liquid to a respective channel. Core-shell droplets may be formed by forming Taylor cones through the application of an electric field. The core-shell droplets may include a core liquid enclosed within a shell liquid, wherein the two liquids may be immiscible.

Abstract: Techniques for manufacturing miniaturized diaphragm pumps using additive manufacturing techniques, such as polyjet printing, are provided, as are the pumps and systems that result from using such techniques to produce the pumps. The provided pumps include a compression chamber that has a first surface, a second opposed surface, and a conical outer wall that extends between the first surface and the second surface and that has a bowed configuration in which the outer wall has a generally concave shape. A diaphragm is disposed proximate to the compression chamber, and the pump also includes one or more valves that control the flow of fluid between the compression chamber and one more fluid ports. Fluid can be selectively vacuumed into and exhausted out of the compression chambers. Various manufacturing techniques for fabricating the pumps are also provided.

Abstract: An x-ray source for use in Phase Contrast Imaging is disclosed. In particular, the x-ray source includes a cathode array of individually controlled field-emission electron guns. The field emission guns include very small diameter tips capable of producing a narrow beam of electrons. Beams emitted from the cathode array are accelerated through an acceleration cavity and are directed to a transmission type anode, impinging on the anode to create a small spot size, typically less than five micrometers. The individually controllable electron guns can be selectively activated in patterns, which can be advantageously used in Phase Contrast Imaging.

Abstract: Described here is a method for performing phase contrast imaging using an array of independently controllable x-ray sources. The array of x-ray sources can be controlled to produce a distinct spatial pattern of x-ray radiation and thus can be used to encode phase contrast signals without the need for a coded aperture. The lack of coded aperture increases the flexibility of the imaging method. For instance, because a fixed, coded aperture is not required, the angular resolution of the imaging technique can be increased as compared to coded-aperture imaging. Moreover, the lack of a radioopaque coded aperture increases the photon flux that reaches the subject, thereby increasing the attainable signal-to-noise ratio.

Abstract: Microplasma generators and associated arrays and methods are described herein. Certain embodiments relate to a microplasma generator in which an elongated semiconductor structure can control electronic current supplied to a microplasma cavity. In certain cases, the microplasma generator can be configured to generate a microplasma when a voltage is applied across the elongated semiconductor structure. Some embodiments include particular spatial arrangements between the electrode(s), the elongated semiconductor structure, and/or the microplasma cavity.

Abstract: Systems and methods in which the flow of fluid is electrically driven, including electrospinning and electrospraying systems and methods, are generally described.

Abstract: Systems and methods in which the flow of fluid is electrically driven, including electrospinning and electrospraying systems and methods, are generally described.

Abstract: Articles and methods involving sensors and thin films suitable for use in sensors are generally provided. In some embodiments, the sensors may comprise a graphene oxide component and/or a thin film with a percolated structure. The sensors may have one or more advantageous properties, such as an appropriate value of resistance, a high degree of sensitivity, and a low response time.

Abstract: Electrospraying systems and associated methods are generally described.

Abstract: Systems and methods in which the flow of fluid is electrically driven, including electrospinning and electrospraying systems and methods, are generally described.

Abstract: Methods for fabrication of self-aligned gated tip arrays are described. The methods are performed on a multilayer structure that includes a substrate, an intermediate layer that includes a dielectric material disposed over at least a portion of the substrate, and at least one gate electrode layer disposed over at least a portion of the intermediate layer. The method includes forming a via through at least a portion of the at least one gate electrode layer. The via through the at least one gate electrode layer defines a gate aperture. The method also includes etching at least a portion of the intermediate layer proximate to the gate aperture such that an emitter structure at least partially surrounded by a trench is formed in the multilayer structure.

Abstract: A microvalve device is provided that includes a through via located in an island structure supported on a thermally-insulating membrane supported by a frame. The through via is surrounded by a meltable sealing material. A heater element is positioned on the island structure for sealing the material over the through via by heating the sealing material.

Abstract: Systems and methods in which the flow of fluid is electrically driven, including electrospinning and electrospraying systems and methods, are generally described.

Abstract: Electrospraying systems and associated methods are generally described.

Abstract: Methods for fabrication of self-aligned gated tip arrays are described. The methods are performed on a multilayer structure that includes a substrate, an intermediate layer that includes a dielectric material disposed over at least a portion of the substrate, and at least one gate electrode layer disposed over at least a portion of the intermediate layer. The method includes forming a via through at least a portion of the at least one gate electrode layer. The via through the at least one gate electrode layer defines a gate aperture. The method also includes etching at least a portion of the intermediate layer proximate to the gate aperture such that an emitter structure at least partially surrounded by a trench is formed in the multilayer structure.

Abstract: Methods for pumping a chamber to generate substantially adsorbate-free surfaces are described. Pumping systems for achieving a vacuum based on surface adsorption are also described.

Abstract: Microplasma generators and associated arrays and methods are described herein. Certain embodiments relate to a microplasma generator in which an elongated semiconductor structure can control electronic cun'ent supplied to a microplasma cavity. Plasmas can be created by supplying energy to a neutral gas so that free electrons and ions are created.