Cavitation sensor

Patent metadata

Field	Value
Publication number	US-9389160-B2
Application number	US-201013878536-A
Country	US
Kind code	B2
Filing date	Oct 15, 2010
Priority date	Oct 15, 2010
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

Abstract

According to various embodiments, a cavitation sensor for detecting bubbles in a liquid is provided. The cavitation sensor may include: a substrate having an insulative surface; and an electrode arrangement provided on or within the insulative surface of the substrate. The electrode arrangement may include a first electrode and a second electrode being isolated from each other by the insulative surface, each of the first and the second electrode including a sensing portion. The spacing between the sensing portion of the first electrode and the sensing portion of the second electrode is adapted to allow charge flow between the first electrode and the second electrode caused by cavitation occurring at the sensing portion.

First claim

The invention claimed is:

1. A cavitation sensor for detecting bubbles in a liquid, the cavitation sensor comprising:
a substrate having an insulative surface; and
an electrode arrangement provided on or within the insulative surface of the substrate; wherein the electrode arrangement comprises a first electrode and a second electrode being isolated from each other by the insulative surface, each of the first and the second electrode comprising a sensing portion, wherein a spacing between the sensing portion of the first electrode and the sensing portion of the second electrode is adapted to allow charge flow between the first electrode and the second electrode caused by cavitation occurring at the sensing portion;
wherein the sensing portion of the first electrode and the sensing portion of the second electrode are configured to remain stationary relative to the substrate, to detect a change in a velocity of liquid flowing parallel to the substrate surface where the electrode arrangement is provided on.

2. The cavitation sensor of claim 1 , wherein the electrode arrangement is a layer having a thickness of around 300 nm.

3. The cavitation sensor of claim 1 , wherein the sensing portion of the first electrode and the sensing portion of the second electrode each comprise a strip.

4. The cavitation sensor of claim 3 , wherein the strip of the first electrode has an end which is disc shaped, while the strip of the second electrode has an end that partially surrounds the disc shaped end of the first electrode to form a crook shape.

5. The cavitation sensor of claim 3 , further comprising a tapered portion formed by the spacing between the strip of the first electrode and the strip of the second electrode tapering towards the corresponding end of the first electrode and the second electrode.

6. The cavitation sensor of claim 3 , wherein the strip of the first electrode is parallel to the strip of the second electrode.

7. The cavitation sensor of claim 6 , wherein the ratio of the space between the strip of the first electrode and the strip of the second electrode; and the width of the strip of the first electrode and the strip of the second electrode is any one of the values of 1, 1.5, 1.75 and 2.

8. The cavitation sensor of claim 1 , wherein the electrode arrangement comprises one or more arrays, each array comprising one or more pairs of first electrodes and second electrodes.

9. The cavitation sensor of claim 8 , wherein each array comprises
a first common terminal to which each of the first electrodes of the one or more pairs are coupled; and
a second common terminal to which each of the second electrodes of the one or more pairs are coupled.

10. The cavitation sensor of claim 9 , wherein the pairs of electrodes are arranged such that first electrodes and second electrodes alternate with each other.

11. The cavitation sensor of claim 10 ,
wherein the first common terminal and the second common terminal are arranged parallel to each other,
wherein the first and second electrodes are arranged parallel to each other, and
wherein the first and second electrodes are arranged perpendicular to the first common terminal and the second common terminal.

12. The cavitation sensor of claim 9 , wherein the first common terminals of a first array of the one or more arrays and a second array of the one or more arrays are coupled together, or wherein the second common terminals of the first array and the second array are coupled together.

13. The cavitation sensor of claim 8 , wherein the distance between adjacent electrodes for one of the one or more arrays is different from the distance between adjacent electrodes for another of the one or more arrays.

14. The cavitation sensor of claim 8 , wherein the distance between adjacent electrodes in all of the one or more arrays is the same.

15. The cavitation sensor of claim 8 , wherein the maximum distance between adjacent electrodes for the one or more arrays is about less than half of the diameter of the bubble to be detected.

16. The cavitation sensor of claim 1 , wherein the spacing between the sensing portion of the first electrode and the sensing portion of the second electrode is smaller than a diameter of a bubble to be detected.

17. The cavitation sensor of claim 1 , wherein the maximum spacing between the sensing portion of the first electrode and the sensing portion of the second electrode is about less than half of the diameter of the bubble to be detected.

18. The cavitation sensor of claim 1 , wherein the sensing portion of the first electrode and the sensing portion of the second electrode are provided on a common plane.

19. The cavitation sensor of claim 1 , wherein the sensing portion of the electrode arrangement is provided on the insulative surface of the substrate, while at least a portion of the remainder of the electrode arrangement is provided within the insulative surface of the substrate.

20. The cavitation sensor of claim 1 , wherein the substrate is entirely made of an insulative material.

Assignees

• Ohl Claus-Dieter
• Gonzalez-Avila Silvestre Roberto
• Univ Nanyang Tech

Inventors

• Ohl Claus-Dieter
• Gonzalez-Avila Silvestre Roberto

Classifications

• G01N13/00 Primary

  Investigating surface or boundary effects, e.g. wetting power; Investigating diffusion effects; Analysing materials by determining surface, boundary, or diffusion effects (scanning-probe techniques or apparatus G01Q) · CPC title

• G01N27/06

  of a liquid (involving electrolysis G01N27/26) · CPC title

• G01N27/07 Primary

  Construction of measuring vessels; Electrodes therefor · CPC title