Abstract: In an aspect, provided herein are 3D-printed textiles, such as spacer fabrics. The textiles can have structures and properties that are not possible when made using conventional technologies having knitting, weaving, or sewing needles. For example, the textiles described herein can have variable yarn thickness, variable connectivity between sheets, and even sheets that intersect each other. Also provided herein are methods for making such textiles.

Abstract: Provided herein are systems and methods for efficiently printing 3D articles from a photo-curable resin. The systems and methods may iteratively execute a print file having instructions for printing the article, where a subsequent iteration may begin before a prior iteration has completed printing. In some embodiments, multiple iterations of an article may be printed onto a substrate as the substrate is moved into a vat of resin at an acute angle relative to the surface of the resin. Different portions of the multiple iterations of the article at respective intersection cut heights may be printed simultaneously within the same merged projection plane.

Abstract: Provided herein are systems and methods for 3D printing. The method can include providing a material model of a volume of photo-curable resin contained in a 3D printer, where a portion of the photo-curable resin is suitable for contact with radiation to cure a portion thereof. The systems and methods can further include providing a geometric model of a 3D object to be printed and choosing a printing methodology comprising a geometry and intensity of radiation to be projected onto the photo-curable resin as a function of time and a control parameter of the 3D printer. The systems and methods can further include minimizing an error between the cured portion of photo-curable resin as predicted by the material model of the photo-curable resin and the geometric model of the 3D object to be printed.

Abstract: The methods is provided for 3D-printing a polymeric scaffold which can have a large cross-sectional area, but can be porous, such that the printed portion of the scaffold has features with dimensions that allow rapid resin recoating without the mechanical assistance of a recoating blade. This 3D-printed scaffold can then be immersed in a polymeric precursor (e.g., comprising monomers and/or oligomers) that flows into and is retained in the scaffold. Excess polymeric precursor can be removed (e.g., washed) from the exterior of the scaffold. The entrained polymeric precursor can then be polymerized to create a polymeric object. The polymeric object can have a large cross-sectional area, a high bulk density, and other desirable properties. The other properties can be achieved by having two intertwined but not homogenously mixed polymers that each have their individual properties, but work to impart desirable properties on the polymeric object as a whole.

Abstract: Provided herein are systems and methods for forming a polymeric object. The systems and methods can use monomers having a first type of functional group that is capable of polymerizing upon exposure to radiation and a second type of functional group that is capable of polymerizing at a second condition. The monomers can be polymerized such that the polymeric object has a first and a second network of linkages.

Abstract: Provided herein are methods for supporting a 3D-printed article while it is being produced. The methods can include printing the support structure along with the article, where the article can be removed from the support structure after the production process. In some embodiments, a method includes: determining a concave hull from an article to be 3D-printed, wherein the article to be 3D-printed comprises a plurality of fibers; determining one or more support pillars for connecting the article to be 3D-printed and a support surface; and printing the one or more support pillars and the article to be 3D-printed together using a 3D printing method. Also provided herein are methods for determining the geometry of the support structure and the supported 3D-printed article produced by the methods described herein.

Abstract: Systems, methods, and new file formats are provided for printing 3D microstructures. In some implementations, a new file format is provided that defines 3D objects by a wireframe model expressed as a collection of wires. Because wires and their parameters are defined within the new file format, objects may be processed more efficiently and quickly to support 3D rendering operations. Such methods may be used to print new articles, such as eyelashes, bushes, swabs and other novel items.

Abstract: Systems, methods, and new file formats are provided for printing 3D microstructures. In some implementations, a new file format is provided that defines 3D objects by a wireframe model expressed as a collection of wires. Because wires and their parameters are defined within the new file format, objects may be processed more efficiently and quickly to support 3D rendering operations. Such methods may be used to print new articles, such as eyelashes, bushes, swabs and other novel items.

Abstract: Provided herein are systems and methods for printing a 3D object on a pliable substrate. In some aspects, the pliable substrate is moved through a vat of polymeric precursor while a mechanism (e.g., having opposing belts) maintains contact with the peripheral edges of the substrate. The systems and methods described herein can have certain advantages, such as precise control over the pliable substrate, allowing for precision printing of 3D articles.

Abstract: Systems, methods, and new file formats are provided for printing 3D microstructures. In some implementations, a new file format is provided that defines 3D objects by a wireframe model expressed as a collection of wires. Because wires and their parameters are defined within the new file format, objects may be processed more efficiently and quickly to support 3D rendering operations. Such methods may be used to print new articles, such as eyelashes, bushes, swabs and other novel items.

Abstract: Systems, methods, and new file formats are provided for printing 3D microstructures. In some implementations, a new file format is provided that defines 3D objects by a wireframe model expressed as a collection of wires. Because wires and their parameters are defined within the new file format, objects may be processed more efficiently and quickly to support 3D rendering operations. Such methods may be used to print new articles, such as eyelashes, bushes, swabs and other novel items.

Abstract: Systems, methods, and new file formats are provided for printing 3D microstructures. In some implementations, a new file format is provided that defines 3D objects by a wireframe model expressed as a collection of wires. Because wires and their parameters are defined within the new file format, objects may be processed more efficiently and quickly to support 3D rendering operations. Such methods may be used to print new articles, such as eyelashes, bushes, swabs and other novel items.

Abstract: Systems, methods, and new file formats are provided for printing 3D microstructures. In some implementations, a new file format is provided that defines 3D objects by a wireframe model expressed as a collection of wires. Because wires and their parameters are defined within the new file format, objects may be processed more efficiently and quickly to support 3D rendering operations. Such methods may be used to print new articles, such as eyelashes, bushes, swabs and other novel items.

Abstract: Systems, methods, and new file formats are provided for printing 3D microstructures. In some implementations, a new file format is provided that defines 3D objects by a wireframe model expressed as a collection of wires. Because wires and their parameters are defined within the new file format, objects may be processed more efficiently and quickly to support 3D rendering operations. Such methods may be used to print new articles, such as eyelashes, bushes, swabs and other novel items.

Abstract: A transformer and associated rectifier for supplying low voltage (e.g. 5 volts), high current (e.g. 1,500 amperes) power to a load such as a supercomputer, with a high electrical conversion efficiency and a high volumetric efficiency. The primary winding comprises a number of disc-shaped coils which are spaced apart from each other by coaxial single turn secondary coil elements which are interleaved between the primary coils. A core having E-shaped parts has an inner portion extending through the primary and secondary coils and an outer portion forming two windows with the inner portion, so that the coils extend through the windows. A rectifier assembly is mounted directly to plates which support and act as terminals to the secondary coils.

Abstract: A power supply circuit capable of operation with 115 V.A.C. (low range) or 230 V.A.C. (high range) line voltages, having a transformer with a primary winding arrangement which can be switched by a relay to accomodate either voltage range. A line voltage sensing circuit is coupled to a low voltage tap on the primary winding to sense the line voltage. When the line voltage is in the high range the voltage sensing circuit leaves the relay de-energized; and the sensing circuit energizes the relay to switch the primary winding to the appropriate configuration when the line voltage is in the low range.

Abstract: A power supply for a load such as a computer, which is sensitive to power interruptions. A switching regulator is coupled to both the AC power line and a rechargeable battery, and makes automatic transitions between AC operation and battery operation, utilizing a transistor switch and an energy storage transformer coupled to both power sources and to the load. The transistor switch is driven by a variable duty cycle control signal provided by a programmed current feedback circuit responsive to both output voltage and instantaneous switch current. The feedback circuit cuts off the switch each time the peak current through the switch reaches a value corresponding to the desired output voltage--thus improving control loop stability and maintaining a constant peak current through the switch to substantially eliminate ripple. The circuit enables one terminal of the battery to be connected to one terminal of the switching transistor, to minimize noise.

Abstract: Filter circuits of the type having inductance and capacitance elements, wherein the number of magnetic components is reduced by using two transformers to perform the functions of four individual inductors. Each transformer has one end of the primary winding connected to one end of the secondary winding, and a pi or T equivalent circuit in which one of the inductance values is equal in magnitude and opposite in sign to a corresponding equivalent circuit inductance value of the other transformer.

Abstract: A ground fault detector for protecting an electrical power system against ground leakage currents. The detector is of the differential transformer type, in which the primary windings of the transformer are connected in series with the hot and neutral lines of the power system, any unbalance in the currents flowing through these lines being detected by sensing the unbalance voltage induced in the secondary winding of the transformer. The secondary voltage is amplified and employed to actuate a solenoid which trips the system circuit breaker in response to unbalance in line and neutral currents due to the flow of ground leakage current. A secondary winding on the solenoid is connected in the neutral line to cause the detector to operate in response to a neutral to ground fault, which might otherwise go undetected.