LIQUID METAL EJECTOR DUAL SENSOR SYSTEM AND METHODS THEREOF

1 . A metal ejecting apparatus, comprising:

a structure defining an inner cavity to receive a metal printing material;

a nozzle orifice in connection with the inner cavity and configured to eject one or more droplets of a liquid metal comprising the metal printing material; and

a first sensor pair in contact with an internal surface of a lower portion of the inner cavity.

2 . The metal ejecting apparatus of claim 1 , wherein each sensor in the first sensor pair is positioned on a first equivalent horizontal plane.

3 . The metal ejecting apparatus of claim 1 , further comprising a second sensor pair in contact with an internal surface of an upper portion of the inner cavity.

4 . The metal ejecting apparatus of claim 3 , wherein each sensor in the second sensor pair is positioned on a second equivalent horizontal plane.

5 . The metal ejecting apparatus of claim 1 , further comprising a heating element configured to heat a solid in the inner cavity of the metal ejecting apparatus, thereby causing the solid to change to a liquid within the metal ejecting apparatus.

6 . The metal ejecting apparatus of claim 1 , further comprising:

a coil wrapped at least partially around the metal ejecting apparatus; and

a power source configured to supply one or more pulses of power to the coil, which cause one or more droplets of liquid metal to be jetted out of the nozzle orifice.

7 . The metal ejecting apparatus of claim 3 , wherein the first sensor pair and the second sensor pair are fixedly attached to the structure defining the inner cavity.

8 . The metal ejecting apparatus of claim 3 , wherein the first sensor pair comprise a non-wetting material when in contact with the liquid metal and the second sensor pair comprise a non-wetting material when in contact with the liquid metal.

9 . The metal ejecting apparatus of claim 8 , wherein the non-wetting material on the first sensor pair comprise boron nitride and non-wetting material on the second sensor pair comprise boron nitride.

10 . The metal ejecting apparatus of claim 1 , wherein the first sensor pair is electrically connected to a printing material feed system.

11 . The metal ejecting apparatus of claim 3 , wherein the second sensor pair is electrically connected to a printing material feed system.

12 . The metal ejecting apparatus of claim 1 , wherein the metal ejecting apparatus further comprises a discrete and separable upper pump segment and a discrete and separable lower pump segment.

13 . The metal ejecting apparatus of claim 12 , wherein the first sensor pair is fixedly attached to the upper pump segment.

14 . The metal ejecting apparatus of claim 12 , wherein the upper pump segment comprises boron nitride.

15 . The metal ejecting apparatus of claim 12 , wherein the lower pump segment comprises graphite.

16 . The metal ejecting apparatus of claim 3 , wherein:

a printing material feed system is configured to receive a first electrical signal indicative of an electrical connection from the first sensor pair when the metal printing material bridges the electrical connection between each sensor in the first sensor pair; and

the printing material feed system is configured to receive a second electrical signal indicative of an electrical connection from the second sensor pair when the metal printing material bridges the electrical connection between each sensor in the first sensor pair.

17 . A metal ejecting apparatus, comprising:

a structure defining an inner cavity to receive a metal printing material, the structure comprising a discrete and separable upper pump segment and a discrete and separable lower pump segment;

a nozzle orifice in connection with the inner cavity and configured to eject one or more droplets of a liquid metal comprising the metal printing material;

a first sensor pair in contact with an internal surface of the inner cavity and fixedly attached to a lower portion of the upper pump segment; and

a second sensor pair in contact with an internal surface of the inner cavity and fixedly attached to an upper portion of the upper pump segment.

18 . The metal ejecting apparatus of claim 17 , further comprising:

a heating element configured to heat a solid in the inner cavity of the metal ejecting apparatus, thereby causing the solid to change to a liquid within the metal ejecting apparatus; and

a coil wrapped at least partially around the metal ejecting apparatus; and

a power source configured to supply one or more pulses of power to the coil, which cause one or more droplets of liquid metal to be jetted out of the nozzle orifice.

19 . The metal ejecting apparatus of claim 17 , wherein:

each sensor in the first sensor pair is positioned on first equivalent horizontal plane; and

each sensor in the second sensor pair is positioned on a second equivalent horizontal plane.

20 . The metal ejecting apparatus of claim 17 , wherein the upper pump segment comprises boron nitride.

21 . The metal ejecting apparatus of claim 17 , wherein the lower pump segment comprises graphite.

22 . A method of controlling level in a metal jetting apparatus, comprising:

receiving a first electrical signal from a first sensor pair in contact with an internal surface of a lower portion of an inner cavity of the metal jetting apparatus;

initiating a feed mechanism of a solid printing material into the inner cavity of the metal jetting apparatus when the first electrical signal is not indicative of an electrical connection between each sensor in the first sensor pair;

receiving a second electrical signal from a second sensor pair in contact with an internal surface of an upper portion of the inner cavity of the metal jetting apparatus; and

pausing the feed mechanism of the solid printing material into the inner cavity of the metal jetting apparatus when the second electrical signal is indicative of an electrical connection between each sensor in the second sensor pair.

23 . The method of controlling level in a metal jetting apparatus of claim 22 , further comprising initiating the feed mechanism of the solid printing material into the inner cavity of the metal jetting apparatus when the second electrical signal is not indicative of electrical connection between each sensor in the second sensor pair.

24 . The method of controlling level in a metal jetting apparatus of claim 22 , further comprising continuing the feed mechanism of the solid printing material into the inner cavity of the metal jetting apparatus when the first electrical signal is indicative of electrical connection between each sensor in the first sensor pair and the second electrical signal is not indicative of electrical connection between each sensor in the second sensor pair.

25 . The method of controlling level in a metal jetting apparatus of claim 22 , wherein the printing material comprises a metal, a metallic alloy, or a combination thereof.

26 . The method of controlling level in a metal jetting apparatus of claim 25 , wherein the printing material comprises aluminum.

27 . The method of controlling level in a metal jetting apparatus of claim 22 , wherein:

the first electrical signal is indicative of electrical connection between each sensor in the first sensor pair when in contact with a molten metal printing material; and

the first electrical signal is not indicative of electrical connection between each sensor in the first sensor pair when not in contact with the molten metal printing material.

28 . The method of controlling level in a metal jetting apparatus of claim 22 , wherein:

the second electrical signal is indicative of electrical connection between each sensor in the second sensor pair when in contact with a molten metal printing material; and

the second electrical signal is not indicative of electrical connection between each sensor in the second sensor pair when not in contact with the molten metal printing material.