Hierarchical branched micro-truss structure and methods of manufacturing the same

• US 9,771,998 B1
• Filed: 08/18/2014
• Issued: 09/26/2017
• Est. Priority Date: 02/13/2014
• Status: Active Grant

• Current Assignee: HRL Laboratories LLC (The Boeing Co.)
• Original Assignee: HRL Laboratories LLC (The Boeing Co.)
• Inventors: Schaedler, Tobias A., Yang, Sophia S., Jiang, Jie, Eckel, Zak C., Roper, Christopher S.
• Primary Examiner(s): Kianni, Kaveh C
• Assistant Examiner(s): Lam, Hung
• Application Number:
  US14/462,508
• Time in Patent Office: 1,135 Days
• Field of Search: 385 9, 385 14, 385 45, 385 46, 385 95, 385120, 385125, 385129-132
• CPC Class Codes: F16F 7/121 the members having a cellular, e.g. honeycomb, structure
• CPC Class Codes: F16F 7/125 Units with a telescopic-like action as one member moves into, or out of a second member F16F7/124, F16F7/127, F16F7/128 take precedence
• CPC Class Codes: G02B 6/02033 Core or cladding made from organic material, e.g. polymeric material G02B1/04 takes precedence
• CPC Class Codes: G02B 6/12002 Three-dimensional structures
• CPC Class Codes: G02B 6/138 by using polymerisation
• CPC Class Codes: G03F 7/0005 Production of optical devices or components in so far as characterised by the lithographic processes or materials used therefor
• CPC Class Codes: G03F 7/0037 Production of three-dimensional images
• CPC Class Codes: G03F 7/30 Imagewise removal using liquid means

Abstract

Branched hierarchical micro-truss structures may be incorporated into energy-absorbing structures to exhibit a tailored multi-stage buckling response to a range of different compressive loads. Branched hierarchical micro-truss structures may also be configured to function as vascular systems to deliver fluid for thermal load management or altering the aerodynamic properties of a vehicle or structure into which the branched hierarchical micro-truss structure is incorporated. The branched hierarchical micro-truss structure includes a first layer having a series of interconnected struts and a second layer having a series of struts branching outward from an end of each of the struts in the first layer.

Claims

1. A branched hierarchical micro-truss structure, comprising:

a first layer comprising a plurality of interconnected struts; and

a second layer comprising a plurality of struts branching outward from an end of each of a plurality of the struts in the first layer, each strut in the second layer having a first end at the end of one of the struts in the first layer and a second end opposite the first end,

wherein a number of struts in the second layer is greater than a number of struts in the first layer,

wherein a first group of struts in the second layer is separated from a second group of struts in the second layer adjacent to the first group, the first group of struts in the second layer branching out from one of the plurality of struts in the first layer and the second group of struts in the second layer branching out from another one of the plurality of struts in the first layer, and

wherein the second ends of the first group of struts in the second layer are not directly connected to the second ends of the second group of struts in the second layer.

2. The micro-truss structure of claim 1, wherein a diameter of the struts in the second layer is less than a diameter of the struts in the first layer.

3. The micro-truss structure of claim 1, wherein a length of the struts in the second layer is less than a length of the struts in the first layer.

4. The micro-truss structure of claim 1, wherein the struts of the first and second layers are solid cylindrical rods.

5. The micro-truss structure of claim 1, wherein:

the plurality of struts in the first layer are arranged in a square-based pyramid configuration or a tetrahedral configuration; and

the plurality of struts branching out from the ends of each of the plurality of struts in the first layer are arranged in a square-based pyramid configuration or a tetrahedral configuration.

6. The micro-truss structure of claim 1, further comprising a third layer, the third layer comprising a plurality of struts branching out from the second ends of each of a plurality of the struts in the second layer.

7. The micro-truss structure of claim 1, wherein the plurality of struts in each of the first layer and the second layer are polymer optical waveguides.

8. The micro-truss structure of claim 1, further comprising a facesheet coupled to ends of a plurality of struts in an outermost one of the layers.