Abstract: A sandwich material having both structural strength and significant acoustic attenuation. In one embodiment, a sandwich is composed of an architected core secured between two facesheets, with a compliant layer forming the connection between the core and the facesheets. The compliant core has a low modulus, resulting in a low speed for elastic shear waves in the sandwich, at low static loads. At high static loads the compliant material stiffens and allows the sandwich to exhibit significant structural strength.

Abstract: A composition for forming a microlattice structure includes a photopolymerizable compound and a flame retardant material. A microlattice structure includes a plurality of struts interconnected at a plurality of nodes, the struts including: a copolymer including a reaction product of a photopolymerizable compound and a flame retardant material. A microlattice structure includes a plurality of struts interconnected at a plurality of nodes, the struts including: a polymer including a reaction product of a photopolymerizable compound; and a flame retardant material.

Abstract: A method for fabricating a radiation-cured structure is provided. The method includes the steps of providing a first radiation-sensitive material and applying a second radiation-sensitive material to the first radiation-sensitive material. The first radiation-sensitive material has a first sensitivity. The second radiation-sensitive material has a second sensitivity different from the first sensitivity. At least one mask is placed between at least one radiation source and the first and second radiation-sensitive materials. The mask has a plurality of substantially radiation-transparent apertures. The first and second radiation-sensitive materials are then exposed to a plurality of radiation beams through the radiation-transparent apertures in the mask to form a first construct in the first radiation-sensitive material and a second construct in the second radiation-sensitive material. The first construct and the second construct cooperate to form the radiation-cured structure.

Abstract: Various implementations and embodiments relate to three-dimensional open cellular diamond micro-truss structures and methods.

Abstract: In one embodiment, provided is a sound attenuating barrier having a core structure between face sheets with a mass attached to at least one face sheet, and having a spatially varied stiffness distribution and/or a spatially varied density. The sound attenuating barrier may include at least one face sheet and/or core having a spatially varied stiffness distribution and/or a spatially varied mass distribution. In one embodiment, a sound attenuating barrier is provided having a core structure between face sheets with a mass structure attached to at least one face sheet, with the core/and or face sheet(s) being constructed to design an effective vibration length as well as enable a variable local stiffness and mass across the sound attenuating barrier such that the sandwich structure provides variable resonance frequency responses and broadband coverage.

Abstract: Composite materials with high damping and high stiffness at relatively low density. These materials include three-dimensional structures of interconnected ligaments, which have multiple concentric layers alternating between stiff constraining layers and soft damping layers, so that bulk deformation of the structure results in high local shear strain and correspondingly high bulk damping.

Abstract: A metal microparticle coated with metal hydride nanoparticles is disclosed. Some variations provide a material comprising a plurality of microparticles (1 micron to 1 millimeter) containing a metal or metal alloy and coated with a plurality of nanoparticles (less than 1 micron) containing a metal hydride or metal alloy hydride. The invention eliminates non-uniform distribution of sintering aids by attaching them directly to the surface of the microparticles. No method is previously known to exist which can assemble nanoparticle metal hydrides onto the surface of a metal microparticle. Some variations provide a solid article comprising a material with a metal or metal alloy microparticles coated with metal hydride or metal alloy hydride nanoparticles, wherein the nanoparticles form continuous or periodic inclusions at or near grain boundaries within the microparticles.

Abstract: A curved sandwich impact structure for a vehicle having a micro-truss core. In one embodiment, the sandwich impact structure includes a micro-truss layer sandwiched between two facesheets, a micro-truss layer designed for energy absorption on the outside of one of the facesheets, and a fascia panel in contact with the energy absorbing micro-truss layer.

Abstract: A process for fabricating a curved beam including a micro-truss structure. In one embodiment, the process includes fabricating the micro-truss structure on a bottom facesheet, where the micro-truss structure is only partially cured so that it is readily bendable, and then forming the partially cured micro-truss structure and bottom facesheet over a curved fixture, where the partially cured micro-truss structure is then fully cured and hardened to its final curved state. A top facesheet is then adhered to a top surface of the micro-truss structure. In an alternate embodiment, a curved bottom facesheet is forced flat against a fixture and the micro-truss structure is formed while the bottom facesheet is secured to the fixture to a partially cured state. The bottom facesheet is then released from the fixture, which causes it to return to its curved configuration causing the micro-truss structure to bend.

Abstract: A three-dimensional microlattice structure includes a series of interconnected struts extending along at least three different directions, a series of intermediate nodes defined at intersections between the struts, and a basal plane structure extending laterally between and interconnecting at least two of the nodes. The basal plane structure may be configured to transversely and rotationally constrain the nodes to increase the overall compressive strength and stiffness of the microlattice structure. In one embodiment, the interconnected struts are arranged into an array of ordered unit cells.

Abstract: A hydrogen storage material has been developed that comprises a metal hydride material embedded into a carbon microstructure that generally exhibits a greater bulk thermal conductivity than the surrounding bulk metal hydride material.

Abstract: A micro-truss based blast protection apparatus. In one embodiment, the blast protection apparatus includes a three-dimensional (3D) ordered truss core between a first face plate and a second face plate. The 3D ordered truss core includes first truss elements defined by first self-propagating polymer waveguides and extending along a first direction, second truss elements defined by second self-propagating polymer waveguides and extending along a second direction, and third truss elements defined by third self-propagating polymer waveguides and extending along a third direction. The first, second, and third truss elements interpenetrate each other at a plurality of nodes to form a continuous material. The first, second, and third truss elements define an open space for providing a densification in response to a force applied to the first face plate and/or the second face plate, and the 3D ordered truss core is self-supporting.

Abstract: A monomeric formulation for fabrication of microlattice structures, the monomeric formulation including a plurality of monomers, a first photoinitiator configured to substantially activate above a wavelength of light, and a second photoinitiator configured not to substantially activate above the wavelength of light and to substantially activate below the wavelength of light.

Abstract: In accordance with various embodiments, a mirror structure is provided having a first face sheet having a mirror surface and a side opposite the mirror surface and a three-dimensional ordered cellular microtruss connected with the side opposite the mirror surface of the first face sheet.

Abstract: Monomeric formulations appropriate for creating self-propagating polymer optical waveguides, and methods for their fabrication, are disclosed. Multiple polymer waveguides can be fabricated simultaneously into a three-dimensional micro-truss structure, while avoiding significant polymerization outside the confines of the illuminated region. The formulations described to accomplish this controlled polymerization include species containing one or more unsaturated carbon-carbon bonds capable of being free-radical polymerized in the presence of photoinitiator and either a radical inhibitor species or a solvent, or both. The radical inhibitor and/or solvent are included to minimize heat buildup and thermal decomposition of initiator. This invention enhances the versatility of the chemistry by significantly increasing the number of chemical building blocks available for micro-truss fabrication.

Abstract: Methods to selectively control the bio-degradation rates of biologically compatible microstructures and methods to control the bio-degradation rates of three-dimensional biological scaffolds, such as ordered open-cellular polymer structures used as biological growth templates are disclosed. Medical uses and application of these materials are disclosed.

Abstract: Methods of manufacturing a structure having at least one plated region and at least one unplated region. The method includes plating a metal on a polymer structure having a first region accepting the metal and a second region unreceptive to the metal plating. The first region may include fully-cured polymer optical waveguides and the second region may include partially-cured polymer optical waveguides. The first region may include a first polymer composition and the second region may include a second polymer composition different than the first polymer composition.

Abstract: An apparatus for maintaining an environmental state of a working surface includes: a first micro-truss layer including: a plurality of first struts extending along a first direction; a plurality of second struts extending along a second direction; and a plurality of third struts extending along a third direction, the first, second, and third struts interpenetrating one another at a plurality of nodes, the first, second, and third struts interpenetrating one another at non-perpendicular angles, the apparatus having a contact surface configured to contact the working surface and having an open porosity configured to allow air to flow to the contact surface, wherein a total surface area of the contact surface is between about 1% and about 50% of a total surface area of the working surface.

Abstract: A monomeric formulation for fabrication of microlattice structures, the monomeric formulation including a plurality of monomers, a first photoinitiator configured to substantially activate above a wavelength of light, and a second photoinitiator configured not to substantially activate above the wavelength of light and to substantially activate below the wavelength of light.

Abstract: A method for fabricating a fuel cell component includes the steps of providing a mask having a plurality of radiation transparent apertures, a radiation-sensitive material having a sensitivity to the plurality of radiation beams, and a flow field layer. The radiation-sensitive material is disposed on the flow field layer. The radiation-sensitive material is then exposed to the plurality of radiation beams through the radiation transparent apertures in the mask to form a diffusion medium layer with a micro-truss structure.