Abstract: Viscoelastic hydrogel microparticles are used for repair of tissue defects and injuries or filling and occlusion of anatomical structures. These are administered as a microparticle suspension using a catheter, syringe, steerable catheter tip, or comparable technology into the site, where they can be further stabilized by crosslinking or sealing, or through incorporation of a support or encapsulating structure. Materials and methods for solidifying, stabilizing and sealing these materials can be used that are also biocompatible and easily deployed with catheters in the body. The micron sized interstitial spacing provides a scaffold for ingrowth and migration of cells into the gel matrices.

Abstract: In one aspect, the present disclosure provides a nozzle for a 3D printing system. The nozzle may include a flowpath with a material inlet and a material outlet. The nozzle may further include a valve in fluid communication with the flowpath between the material inlet and the material outlet, where the valve includes a closed state and an open state, where in the closed state the valve obstructs the flowpath between the material inlet and the material outlet, and where in the open state the material inlet is in fluid communication with the material outlet. The nozzle may further include a compensator in fluid communication with the flowpath, where the compensator includes a contracted state associated with the open state of the valve and an expanded state associated with the closed state of the valve.

Abstract: In one aspect, the present disclosure provides a nozzle for a 3D printing system. The nozzle may include a flowpath with a material inlet and a material outlet. The nozzle may further include a valve in fluid communication with the flowpath between the material inlet and the material outlet, where the valve includes a closed state and an open state, where in the closed state the valve obstructs the flowpath between the material inlet and the material outlet, and where in the open state the material inlet is in fluid communication with the material outlet. The nozzle may further include a compensator in fluid communication with the flowpath, where the compensator includes a contracted state associated with the open state of the valve and an expanded state associated with the closed state of the valve.

Abstract: Generating questions by receiving user utterance data, determining an intent confidence vector for the user utterance data, predicting, by a trained next user-intent prediction model, a next user-intent confidence vector using the intent confidence vector, and generating a next question using the next user-intent confidence vector.

Abstract: A subwavelength resonator for acoustophoretic printing comprises a hollow resonator body for local enhancement of an acoustic field integrated with a nozzle body for delivery of an ink into the acoustic field. The nozzle body has a first end outside the hollow resonator body and a second end inside the hollow resonator body, and includes a fluid channel extending between a fluid inlet at the first end and a fluid outlet at the second end. The fluid channel passes through a side wall of the hollow resonator body and includes at least one bend. During acoustophoretic printing, an ink delivered through the fluid channel of the nozzle body and out of the fluid outlet is exposed to a high-intensity acoustic field.

Abstract: A 3-D printed device comprising one or more structures, the structures comprising a plurality of magnetically responsive particles and one or more diblock or triblock copolymers; the diblock or triblock copolymers having an A-B, A-B-A, or A-B-C block-type structure in which the A-blocks and C-blocks are an aromatic-based polymer or an acrylate-based polymer and the B-blocks are an aliphatic-based polymer. These 3-D printed devices may be formed using a method that comprises providing a magnetic ink composition; applying the magnetic ink composition to a substrate in a 3-D solvent cast printing process to form one or more structures; and drying the one or more structures formed from the magnetic ink composition. The dried structures can exhibit one or more regions of magnetic permeability greater than 1.3×10?6 H/m.

Abstract: A method of controlling macroscopic properties of a metamaterial includes 3D printing a lattice structure comprising interconnected struts, where each strut comprises one or more printed filaments. Each printed filament comprises an active material or a passive material, and the active material has a modulus with a higher stimulus dependence than that of the passive material. The printed filaments comprising the active material are disposed at predetermined regions of the lattice structure. After 3D printing, the lattice structure is exposed to a stimulus, and the predetermined regions comprising the active material soften or stiffen. Thus, the macroscopic properties of the lattice structure may be controlled.

Abstract: A modular roller hemming system having a base assembly, a replaceable anvil, a spider arm assembly, a plurality of support arms for supporting the spider arm assembly, and a plurality of repositionable unit tools. The anvil is 3-D printed of a polymer composite material and may be replaced with similarly manufactured anvils having different form factors for receiving various shaped and dimensioned workpiece assemblies. The plurality of support arms are repositionable on the base assembly, the spider arm assembly is reconfigurable, and the plurality of unit tools are moveable to accommodate various anvils having different form factors. The support arms includes an upper segment that is detachable from the lower segment to facilitate the changeover of anvils.

Abstract: Described herein are methods of generating a programmable multicellular organoid and/or a 3D organ-specific tissue. Also, described are the programmable multicellular organoid and/or a 3D organ-specific tissue produced by the described methods. Also, described herein are in vitro methods of generating functional human tissue construct.

Abstract: A method of printing a cellular solid by direct bubble writing comprises introducing an ink formulation comprising a polymerizable monomer and a gas into a nozzle, which includes a core flow channel radially surrounded by an outer flow channel. The ink formulation is directed into the outer flow channel and the gas is directed into the core flow channel. The ink formulation and the gas are ejected out of the nozzle as a stream of bubbles, where each bubble includes a core comprising the gas and a liquid shell overlying the core that comprises the ink formulation. After ejection, the polymerizable monomer is polymerized to form a solid polymeric shell from the liquid shell, and the bubbles are deposited on a substrate moving relative to the nozzle. Thus, a polymeric cellular solid having a predetermined geometry is printed.

Abstract: A method of forming a three-dimensional structure includes forming a layer of resin comprising liquid crystal oligomers and a photoinitiator, applying a magnetic field to the formed layer in a predefined alignment direction for substantially aligning the liquid crystal oligomers in a first orientation; and exposing the formed layer to radiation for curing a first portion of the layer during application of the magnetic field thereby resulting in the first portion having liquid crystal elastomers substantially aligned in the first orientation. The method includes applying a second magnetic field to the formed layer in a predefined second alignment direction for substantially aligning uncured liquid crystal oligomers in a second orientation, and exposing the layer to radiation for curing a second portion of the layer during application of the second magnetic field thereby resulting in the second portion having liquid crystal elastomers substantially aligned in the second orientation.

Abstract: A method of printing a cellular solid (120) by direct bubble writing comprises introducing an ink formulation (102) comprising a polymerizable monomer and a gas (104) into a nozzle (106), which includes a core flow channel (108) radially surrounded by an outer flow channel (110). The ink formulation is directed into the outer flow channel (110) and the gas is directed into the core flow channel (108). The ink formulation (102) and the gas (104) are ejected out of the nozzle (106) as a stream of bubbles (112), where each bubble includes a core (114) comprising the gas and a liquid shell (116) overlying the core that comprises the ink formulation. After ejection, the polymerizable monomer is polymerized to form a solid polymeric shell (118) from the liquid shell (116), and the bubbles are deposited on a substrate (122) moving relative to the nozzle (106). Thus, a polymeric cellular solid (120) having a predetermined geometry is printed.

Abstract: This disclosure features artificial tympanic membrane graft devices and two-component bilayer graft devices that include a scaffold having a plurality of ribs made of a first material and a plurality of spaces between the ribs filled or made with the first material, a different, second material, a combination of the first and a second materials, or a combination of a second material and one or more other different materials. The bilayer graft devices have two components or layers. One component, e.g., the underlay graft device, can include a projection, and the second component, e.g., the overlay graft device, can include an opening that corresponds to the projection (or vice versa) so that the opening and the projection can secure the two layers together in a “lock and key” manner. This disclosure also features methods of making, using, and implanting the three-dimensional artificial tympanic membrane and bilayer graft devices.

Abstract: A printhead comprises a plurality of ink cartridges and a nozzle, where the nozzle and the ink cartridges are configured to rotate together about an axis during printing. The nozzle includes a nozzle body comprising an inlet end, an outlet end, and one or more internal passageways extending through the nozzle body from the inlet end to the outlet end. The one or more internal passageways terminate at one or more outlets at or near the outlet end. The nozzle also includes plurality of nozzle inlets at the inlet end for delivery of flowable inks into the internal passageways, where each nozzle inlet is in fluid communication with a dispensing end of one of the ink cartridges.

Abstract: Described herein are melt-extrudable biodegradable inks for 3D-printing, methods of using the inks, and kits including the inks, to prepare implantable grafts, such as artificial tympanic membrane devices or artificial cartilage, nerve conduit, tendon, muscle tissue, or bone devices.

Abstract: A method of forming an innervated liquid crystal elastomer (iLCE) actuator comprises extruding a filament through a nozzle moving relative to a substrate, where the filament has a core-shell structure including a shell comprising a liquid crystal elastomer surrounding a core configured to induce a nematic-to-isotropic transition of the liquid crystal elastomer. The filament is subjected to UV curing as the filament is extruded, and the filament is deposited on the substrate as the nozzle moves. A director of the liquid crystal elastomer is aligned with a print path of the nozzle, and a 3D printed architecture configured for actuation is formed.

Abstract: Described are devices and methods for use in connection with organ replacement or organ assist therapy in a patient.

Abstract: A method of acoustophoretic printing comprises generating an acoustic field at a first end of an acoustic chamber fully or partially enclosed by sound-reflecting walls. The acoustic field interacts with the sound-reflecting walls and travels through the acoustic chamber. The acoustic field is enhanced in a chamber outlet at a second end of the acoustic chamber. An ink is delivered into a nozzle positioned within the acoustic chamber. The nozzle has a nozzle opening projecting into the chamber outlet. The ink travels through the nozzle and is exposed to the enhanced acoustic field at the nozzle opening, and a predetermined volume of the ink is ejected from the nozzle opening and out of the acoustic chamber.

Abstract: In one aspect, the present disclosure provides a nozzle for 3-D printing. The nozzle may include a first nozzle tip defining a first outlet, where the first nozzle tip includes a first channel extending therethrough. The nozzle may further include a second nozzle tip defining a second outlet, where the second nozzle tip includes a second channel extending therethrough, and where the first channel surrounds the second outlet. The second nozzle tip may be retracted longitudinally with respect to the first nozzle tip such that the second outlet of the second nozzle tip is located in the first channel.

Abstract: A modular roller hemming system having a base assembly, a replaceable anvil, a spider arm assembly, a plurality of support arms for supporting the spider arm assembly, and a plurality of repositionable unit tools. The anvil is 3-D printed of a polymer composite material and may be replaced with similarly manufactured anvils having different form factors for receiving various shaped and dimensioned workpiece assemblies. The plurality of support arms are repositionable on the base assembly, the spider arm assembly is reconfigurable, and the plurality of unit tools are moveable to accommodate various anvils having different form factors. The support arms includes an upper segment that is detachable from the lower segment to facilitate the changeover of anvils.