Abstract: The present disclosure relates to a device for three-dimensional ink deposition from an impeller-driven active mixing microfluidic printing nozzle. The device is configured to receive a material property associated with the plurality of fluids and receive a structure property of the printing nozzle. The device then determines a threshold relation between a rotating speed ? of an impeller in the nozzle and a volumetric flow rate Q of fluids that flow through the nozzle based on the material property of the plurality of fluids, the structure property of the printing nozzle. Based on the threshold relation, the device then determines an actual volumetric flow rate of the fluids and actual rotation speed of the impeller.

Abstract: A method of 4D printing comprises depositing a layer of filaments in a predetermined arrangement on a flexible substrate. Each filament comprises a hydrogel matrix and a plurality of anisotropic filler particles embedded therein. The filaments contact the flexible substrate at one or more contact regions. The layer of filaments is hydrated, and the filaments swell in size while remaining in contact with the flexible substrate at the contact regions. The flexible substrate is thereby induced to adopt a predetermined curved shape.

Abstract: Method and apparatus for separating a target substance from a fluid or mixture. Capsules having a coating and stripping solvents encapsulated in the capsules are provided. The coating is permeable to the target substance. The capsules having a coating and stripping solvents encapsulated in the capsules are exposed to the fluid or mixture. The target substance migrates through the coating and is taken up by the stripping solvents. The target substance is separated from the fluid or mixture by driving off the target substance from the capsules.

Abstract: A rapid, scalable methodology for graphene dispersion and concentration with a polymer-organic solvent medium, as can be utilized without centrifugation, to enhance graphene concentration.

Abstract: A foam ink composition for printing porous structures comprises stabilizing particles and gas bubbles dispersed in a solvent. The stabilizing particles comprise a predetermined interfacial energy so as to exhibit a contact angle with the solvent of from about 15° to about 90° . At least a portion of the stabilizing particles are positioned at interfacial regions between the solvent and the gas bubbles, thereby stabilizing the gas bubbles in the foam ink composition. A 3D printed hierarchical porous structure comprises one or more continuous filaments arranged in a predetermined pattern on a substrate, the one or more continuous filaments comprising a sintered material and including a porosity of at least about 40 vol. %.

Abstract: The present disclosure relates to a device for three-dimensional ink deposition from an impeller-driven active mixing microfluidic printing nozzle. The device is configured to receive a material property associated with the plurality of fluids and receive a structure property of the printing nozzle. The device then determines a threshold relation between a rotating speed ? of an impeller in the nozzle and a volumetric flow rate Q of fluids that flow through the nozzle based on the material property of the plurality of fluids, the structure property of the printing nozzle. Based on the threshold relation, the device then determines an actual volumetric flow rate of the fluids and actual rotation speed of the impeller.

Abstract: A 3D printed tubular construct, such as a nephron, with or without embedded vasculature as well as methods of printing tubular tissue constructs are described.

Abstract: A rapid, scalable methodology for graphene dispersion and concentration with a polymer-organic solvent medium, as can be utilized without centrifugation, to enhance graphene concentration.

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 under-lay 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: Methods of tissue engineering, and more particularly methods and compositions for generating various vascularized 3D tissues, such as 3D vascularized embryoid bodies and organoids are described. Certain embodiments relate to a method of generating functional human tissue, the method comprising embedding an embryoid body or organoid in a tissue construct comprising a first vascular network and a second vascular network, each vascular network comprising one or more interconnected vascular channels; exposing the embryoid body or organoid to one or more biological agents, a biological agent gradient, a pressure, and/or an oxygen tension gradient, thereby inducing angiogenesis of capillary vessels to and/or from the embryoid body or organoid; and vascularizing the embryoid body or organoid, the capillary vessels connecting the first vascular network to the second vascular network, thereby creating a single vascular network and a perfusable tissue structure.

Abstract: Encapsulated solids are made by first encapsulating precursor materials in a polymer shell. The precursors are some combination of solids, liquids, gases, and/or gels. The precursors are then transformed into solids by emplacement of the capsule in an environment where gas or fluid transport into or out of the polymer shell causes transformation into solids.

Abstract: Aspects of the present invention provide improved methods and apparatus for use in in vitro modeling of the interaction of cells with cellular constructs/parts/axons, including axon mimetics and use of three-dimensional fibers.

Abstract: A multinozzle deposition system for direct write applications comprises a body including a first network of microchannels embedded therein, where the first network of microchannels extends from a parent microchannel through a series of furcations to a plurality of branching microchannels. The series consists of k generations with furcation number m where the kth generation includes mk branching microchannels. A first end of the body includes a single inlet to the parent microchannel and a second end of the body includes mk outlets from the branching microchannels, where k is an integer greater than or equal to 1 and m is an integer greater than or equal to 2. The body comprises a material having a sufficient rigidity to sustain a pressure in the microchannels of about 690 kPa or greater without distortion.

Abstract: A method of 4D printing a hydrogel composite structure comprises depositing a first layer of filaments on a substrate in a first predetermined arrangement, where each filament comprises a hydrogel matrix and a plurality of anisotropic filler particles embedded therein. A second layer of the filaments is deposited in a second predetermined arrangement on the first layer. The filaments from the second layer contact the filaments from the first layer at a number of contact regions. The first layer and the second layer are hydrated, and the filaments of the first and second layers swell in size while remaining in contact at the contact regions. Thus, a curved three-dimensional hydrogel composite structure is formed.

Abstract: A multinozzle deposition system for direct write applications comprises a body including a first network of microchannels embedded therein, where the first network of microchannels extends from a parent microchannel through a series of furcations to a plurality of branching microchannels. The series consists of k generations with furcation number m where the kth generation includes mk branching microchannels. A first end of the body includes a single inlet to the parent microchannel and a second end of the body includes mk outlets from the branching microchannels, where k is an integer greater than or equal to 1 and m is an integer greater than or equal to 2. The body comprises a material having a sufficient rigidity to sustain a pressure in the microchannels of about 690 kPa or greater without distortion.

Abstract: A rapid, scalable methodology for graphene dispersion and concentration with a polymer-organic solvent medium, as can be utilized without centrifugation, to enhance graphene concentration.

Abstract: An energy absorbing cell has a first structural element, a second structural element disposed parallel to and spaced apart from a first structural element, a first intermediate member, and a second intermediate member. Each intermediate member is disposed at an angle between the structural elements. A first end and a second end of each intermediate member are respectively attached to the structural elements. The intermediate members are formed from an elastic material. The angles of the intermediate members are selected such that application of a compressive force to displace the structural elements toward one another triggers a snap-through instability in both intermediate members. The energy absorbing cell is used, singly or in combination with one or more other energy absorbing cells, to form energy absorbing structures, such as vehicle bumpers or highway barriers, adapted to control the deceleration of an object impacting the energy absorbing structure.

Abstract: A 3D printed polishing pad for chemical-mechanical planarization (CMP) comprises a microlattice including a plurality of layers of extruded filaments arranged in a crisscross pattern. The extruded filaments comprise a polymer composite including a thermoset polymer matrix and filler particles dispersed therein, where the filler particles comprise a length or diameter of no greater than about 200 nm. A three-dimensional network of interconnected voids extends through the microlattice.

Abstract: A filamentary structure extruded from a nozzle during 3D printing comprises a continuous filament including filler particles dispersed therein. At least some fraction of the filler particles in the continuous filament comprise high aspect ratio particles having a predetermined orientation with respect to a longitudinal axis of the continuous filament. The high aspect ratio particles may be at least partially aligned along the longitudinal axis of the continuous filament. In some embodiments, the high aspect ratio particles may be highly aligned along the longitudinal axis. Also or alternatively, at least some fraction of the high aspect ratio particles may have a helical orientation comprising a circumferential component and a longitudinal component, where the circumferential component is imparted by rotation of a deposition nozzle and the longitudinal component is imparted by translation of the deposition nozzle.

Abstract: An ink composition for making a conductive silver structure comprises a silver salt and a complex of (a) a complexing agent and a short chain carboxylic acid or (b) a complexing agent and a salt of a short chain carboxylic acid, according to one embodiment. A method for making a silver structure entails combining a silver salt and a complexing agent, and then adding a short chain carboxylic acid or a salt of the short chain carboxylic acid to the combined silver salt and a complexing agent to form an ink composition. A concentration of the complexing agent in the ink composition is reduced to form a concentrated formulation, and the silver salt is reduced to form a conductive silver structure, where the concentrated formulation and the conductive silver structure are formed at a temperature of about 120° C. or less.