Micro sensor system for liquid conductivity, temperature and depth

• US 20070018652A1
• Filed: 02/21/2006
• Published: 01/25/2007
• Est. Priority Date: 02/21/2005
• Status: Active Grant

• Current Assignee: University of South Florida (State University System of Florida)
• Original Assignee: University of South Florida (State University System of Florida)
• Inventors: Fries, David, Steimle, George, Ivanov, Stanislav, Broadbent, Heather
• Granted Patent: US 7,259,566 B2
• Time in Patent Office: Days
• US Class Current: 324/446
• CPC Class Codes: G01N 27/12 of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid , for detecting components in the fluid

Abstract

In accordance with the present invention is a miniature planar oceanographic conductivity, temperature pressure (CTD) system based on a thin film material fabricated on a Liquid Crystalline Polymer (LCP). The micro-CTD system in accordance with the present invention analyzes water for salinity by measuring conductivity, temperature and depth.

Claims

1. An apparatus for measuring conductivity, temperature and depth of a liquid, the apparatus comprising:

a substantially planar thin-film conductivity microsensor for measuring the conductivity of the liquid;

a substantially planar thin-film resistive temperature microsensor for measuring the temperature of the liquid; and

a discrete pressure microsensor for measuring the pressure of the liquid.

2. The apparatus of claim 1, wherein the conductivity microsensor further comprises a four electrode conductivity sensor further comprising four concentric annular electrodes fixed in relative position to each other.

3. The apparatus of claim 1, wherein the substantially planar thin-film conductivity microsensor is fabricated on a liquid crystalline polymer substrate.

4. The apparatus of claim 2, wherein the four concentric annular electrodes are fabricated of electroless nickel and electroless gold.

5. The apparatus of claim 2, wherein the four concentric annular electrodes are fabricated of electroless nickel and electrolytic gold.

6. The apparatus of claim 2, wherein the four concentric annular electrodes are fabricated of electroless nickel, electrolytic gold and platinum black.

7. The apparatus of claim 1, wherein the conductivity microsensor further comprises supply circuitry coupled to the four concentric annular electrodes and output circuitry coupled to the four concentric annular electrodes for measuring the conductivity of the liquid.

8. The apparatus of claim 1, wherein the substantially planar thin-film resistive temperature microsensor further comprises a thin-film metallic circuit exhibiting a linear change in resistance with a change in the temperature of the liquid.

9. The apparatus of claim 1, wherein the substantially planar thin-film resistive temperature microsensor further comprises two parallel metallic traces having 90°

angles and meeting at a center point.

10. The apparatus of claim 1, wherein the substantially planar thin-film resistive temperature microsensor is fabricated on a copper-clad liquid crystalline polymer substrate.

11. The apparatus of claim 1, wherein the discrete pressure microsensor is a piezoresistive pressure sensor.

12. The apparatus of claim 1, wherein the discrete pressure microsensor is a multilayer electrode of LCP/Cu construction adapted to change it'"'"'s dimension in proportion to the contact pressure of the liquid.

13. The apparatus of claim 1, further comprising a data-acquisition and processing system connected to receive measurement signals from the conductivity microsensor, the temperature microsensor and the pressure microsensor.

14. The apparatus of claim 1, further comprising embedded wireless functionality connected to transmit measurement signals from the conductivity microsensor, the temperature microsensor and the pressure microsensor.

15. The apparatus of claim 1, further comprising a substantially watertight casing to protect the apparatus from exposure to the liquid.