Layered energetic material having multiple ignition points

Patent metadata

Field	Value
Publication number	US-9709366-B1
Application number	US-201615243072-A
Country	US
Kind code	B1
Filing date	Aug 22, 2016
Priority date	Mar 14, 2013
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

An energetic material having thin, alternating layers of metal oxide and reducing metal is provided. The energetic material may be provided in the form of a sheet, foil, cylinder, or other convenient structure. A method of making the energetic material resists the formation of oxide on the surface of the reducing metal, allowing the use of multiple thin layers of metal oxide and reducing metal for maximum contact between the reactants, without significant lost volume due to oxide formation. An ignition system for the energetic material includes multiple ignition points, as well as a means for controlling the timing and sequence of activation of the individual ignition points. The combination of the energetic material and ignition system provides a means of charge and blast shaping, ignition timing, pressure curve control and maximization, and safe neutralization of the energetic material.

First claim

What is claimed is:

1. A combination of an energetic material and an ignition system, the combination comprising:
a plurality of nested, generally cylindrical layers of energetic material, the energetic material comprising:
a metal oxide sublayer having a first thickness, the first thickness being between about 5 nm and about 1,000 nm;
a reducing metal sublayer having a second thickness, the second thickness being between about 5 nm and about 1,000 nm; and
an interface between the metal oxide sublayer and reducing metal sublayer, the interface being either substantially free of reducing metal oxide, or the interface being a reducing metal oxide sublayer having an average thickness of less than 2 nm;

an ignition system having a plurality of ignition points, each layer of energetic material having at least one ignition point therein, the ignition points being disposed at predetermined distances from a central axis of the generally cylindrical layers of energetic material;
the ignition system being structured to activate ignition points in a sequence beginning with an exterior of the energetic material, with ignition progressing to ignition points disposed in increasing proximity to the central axis of the layered energetic material; and
the ignition system being further structured to activate the ignition points in a timed relationship with each other, the timed relationship being predetermined to produce a series of pressure waves from all layers that reaches a predetermined point essentially simultaneously.

2. The combination according to claim 1 , further comprising:
a plurality of gaps disposed between some of the layers of energetic material;
a bridge defined in at least one location within each gap, each bridge being a band of energetic material connecting the energetic material on either side of the gap; and
the ignition system having at least one ignition point corresponding to each bridge, each ignition point including a positive land on one side of the bridge, and a negative land on the other side of the bridge, whereby current flowing across the bridge heats the bridge sufficiently to ignite the adjacent energetic material.

3. The combination according to claim 1 :
further comprising a counting circuit, the counting circuit having a plurality of output bits; and
wherein each ignition point is operatively connected to either an output bit or a at least one logical gate, with the logical gate being operatively connected to a combination of output bits, the output bit or combination of output bits corresponding to a predetermined time interval between an initial ignition signal and ignition of each ignition point.

4. The combination according to claim 1 , further comprising a microprocessor, the microprocessor having an output pin operatively connected to each ignition point, the microprocessor being programmable to provide an ignition signal to each ignition point with a predetermined timing and sequence.

5. The combination according to claim 4 , wherein the microprocessor is user-programmable.

6. The combination according to claim 1 , wherein the combination forms an igniter or detonator for another ignitable or explosive material.

7. The combination according to claim 1 , wherein each ignition point includes a fuse assembly operatively connected thereto, each fuse assembly having a length that is proportional to a predetermined time interval between an original ignition signal and a desired ignition signal for each fuse assembly.

8. The combination according to claim 7 , further comprising a plurality of gaps between some layers of energetic material, the gaps separating the energetic material into rings.

9. The combination according to claim 8 , wherein each fuse assembly further comprises:
a first fuse portion associated with each ring of energetic material, all first fuse portions having a common initiation end, the first fuse portions each having a termination end, and each first fuse portion defining a length between the initiation end and termination end, the termination end being disposed substantially along a central axis of the layers of energetic material;
a plurality of second fuse portions associated with each first fuse portion, the second fuse portions having initiation ends operatively connected to the termination end of the first fuse portion with which the second fuse portions are associated, each of the second fuse portions associated with a given first fuse portion terminating in operative connection with the ring of energetic material with which the first fuse portion is associated; and
the length of each first fuse portion being predetermined so that an ignition at the initiation point of the first fuse portions reaches the termination end of the second fuse portions associated with each first fuse portion with a predetermined timing and sequence.

10. The combination according to claim 7 , wherein each fuse assembly further comprises:
a plurality of first fuse portions, all first fuse portions having a common initiation end, the first fuse portions each having a termination end, and each first fuse portion defining a length between the initiation end and termination end, the termination end being disposed substantially along a central axis of the layers of energetic material;
a plurality of second fuse portions associated with each first fuse portion, the second fuse portions having initiation ends operatively connected to the termination end of the first fuse portion with which the second fuse portions are associated, each of the second fuse portions associated with a given first fuse portion terminating at substantially the same distance radially outwardly from the central axis and in operative connection with the energetic material; and
the length of each first fuse portion being predetermined so that an ignition at the initiation point of the first fuse portions reaches the termination end of the second fuse portions associated with each first fuse portion with a predetermined timing and sequence.

11. The combination according to claim 7 , wherein each fuse comprises a zigzag deposition of fuse material.

12. The combination according to claim 1 , further comprising alternating nested generally cylindrical layers of energetic material and high explosive material.

13. The combination according to claim 1 , wherein the combination is of unitary construction, with a portion of the ignition system forming a portion of each layer, each layer having a plurality of ignition signal conductors therewithin, the ignition system further having an ignition point corresponding to each ignition signal conductor.

14. A combination of an energetic material and an ignition system, the combination comprising:
a plurality of layers of energetic material, the energetic material comprising:
a metal oxide sublayer having a first thickness, the first thickness being between about 5 nm and about 1,000 nm;
a reducing metal sublayer having a second thickness, the second thickness being between about 5 nm and about 1,000 nm; and
an interface between the metal oxide sublayer and reducing metal sublayer, the interface being either substantially free of reducing metal oxide, or the interface being a reducing metal oxide sublayer having an average thickness of less than 2 nm;

an ignition system having a plurality of ignition points, each layer of energetic material having at least one ignition point therein, the ignition points being disposed at predetermined distances from a center point of the layers of energetic material;
the ignition system being structured to activate ignition points in a sequence beginning w

Assignees

• Mohler Timothy
• Mohler Jonathan
• Univ Central Florida Res Found Inc
• Spectre Mat Sciences Inc
• Univ Central Florida Res Found Inc

Inventors

• Mohler Timothy
• Mohler Jonathan
• Coffey Kevin R

Classifications

• F42C11/065

  Programmable electronic delay initiators in projectiles · CPC title

• F42B3/122 Primary

  Programmable electronic delay initiators · CPC title

• C06B45/12

  having contiguous layers or zones · CPC title

• F42B3/08

  with cavities in the charge, e.g. hollow-charge blasting cartridges · CPC title

• F42C11/06 Primary

  with time delay by electric circuitry · CPC title