Abstract:
A system for fabricating micro-truss structures. A reservoir holds a volume of a liquid photomonomer configured to polymerize to form a photopolymer when exposed to suitable light such as ultraviolet light. A mask at the bottom of the reservoir includes a plurality of apertures. Light enters the reservoir through each aperture from several directions, forming a plurality of self-guided photopolymer waveguides within the reservoir. The light is supplied by one or more sources of collimated light. A plurality of mirrors may reflect the light from a single source of collimated light to form a plurality of collimated beams, that illuminate the photomonomer in the reservoir, through the mask, from a corresponding plurality of directions, to form a micro-truss structure including a plurality of self-guided waveguide members.
Abstract:
The present invention relates to a micro-lattice and, more particularly, to an ultra-light micro-lattice and a method for forming the same. The micro-lattice is a cellular material formed of interconnected hollow tubes. The cellular material has a relative density in a range of 0.001% to 0.3%, and a density of 0.9 mg/cc has been demonstrated. The cellular material also has the ability to recover from a deformation exceeding 50% strain.
Abstract:
Architected materials with superior energy absorption properties when loaded in compression. In several embodiments such materials are formed from micro-truss structures composed of interpenetrating tubes in a volume between a first surface and a second surface. The stress-strain response of these structures, for compressive loads applied to the two surfaces, is tailored by arranging for some but not all of the tubes to extend to both surfaces, adjusting the number of layers of repeated unit cells in the structure, arranging for the nodes to be offset from alignment along lines normal to the surfaces, or including multiple interlocking micro-truss structures.
Abstract:
A three-dimensional lattice architecture with a thickness hierarchy includes a first surface and a second surface separated from each other with a distance therebetween defining a thickness of the three-dimensional lattice architecture; a plurality of angled struts extending along a plurality of directions between the first surface and the second surface; a plurality of nodes connecting the plurality of angled struts with one another forming a plurality of unit cells. At least a portion of the plurality of angled struts are internally terminated along the thickness direction of the lattice structure and providing a plurality of internal degrees of freedom towards the first or second surface of the lattice architecture.
Abstract:
A sparse micro-truss structure having a series of unit cells arranged in an array is disclosed. Each of the unit cells includes a series of struts interconnected at a node. Adjacent unit cells are spaced apart by a gap. Spacing apart the adjacent unit cells is configured to reduce the sensitivity of the sparse micro-truss structure to premature mechanical failure due to buckling in one or more of the struts compared to related art micro-truss structures having a series of fully interconnected unit cells.
Abstract:
A method of exchanging heat between fluids with a heat Exchanger comprising a three-dimensional ordered microstructure material within a shell. The three-dimensional ordered microstructure material has dimensions that allow for large surface area to volume ratios, between 300 and 15000 m2/m3. Alternatively the three-dimensional ordered microstructure may have an open volume fraction between 0.4 and 0.6. The three-dimensional ordered microstructure may be comprised of hollow truss elements and partially filled with a thermally conductive material or a fluid. The Heat Exchanger has a heat transfer coefficient multiplied by the surface area to volume ratio between 3.7*107 and 7*109 Watts per M3K.
Abstract:
Methods of embedding at least one fastener in a sandwich structure having an ordered three-dimensional microstructure core provided between a pair of facesheets. The method includes attaching the at least one fastener to a first facesheet. The method also includes irradiating a volume of photo-monomer in a reservoir with light beams to form an ordered three-dimensional microstructure core around the at least one fastener. The method also includes attaching a second facesheet to the ordered three-dimensional microstructure core to form the sandwich structure. The fasteners embedded in the sandwich structure are configured to facilitate attachment of the sandwich structure to another structure.
Abstract:
Architected materials with superior energy absorption properties when loaded in compression. In several embodiments such materials are formed from micro-truss structures composed of interpenetrating tubes in a volume between a first surface and a second surface. The stress-strain response of these structures, for compressive loads applied to the two surfaces, is tailored by arranging for some but not all of the tubes to extend to both surfaces, adjusting the number of layers of repeated unit cells in the structure, arranging for the nodes to be offset from alignment along lines normal to the surfaces, or including multiple interlocking micro-truss structures.
Abstract:
A micro-truss fabricated of thermosetting polymer and toughened with a coating of thermoplastic polymer. In one embodiment the thermosetting polymer micro-truss is immersed in a solution of thermoplastic polymer in an organic solvent. The immersion causes the micro-truss to absorb the thermoplastic polymer solution and to become coated with the thermoplastic polymer solution. Subsequent drying of the micro-truss leaves a coating of thermoplastic polymer on the micro-truss, and a layer of thermosetting polymer into which the thermoplastic polymer has penetrated. In another embodiment a thermoplastic monomer solution is allowed to diffuse into, and coat, the thermosetting polymer micro-truss, and the thermoplastic monomer is subsequently polymerized.
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.