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EP-4735865-A1 - SPIRAL IMPEDANCE STRUCTURE

EP4735865A1EP 4735865 A1EP4735865 A1EP 4735865A1EP-4735865-A1

Abstract

An impedance sensing structure is provided and includes a dielectric layer, a spiral electrode pair forming a dual spiral channel on the dielectric layer and having an inlet portion at a central region of the dual spiral channel and an outlet portion at an end of the dual spiral channel, inlet and outlet elements and sensing circuitry. The inlet and outlet elements are coupled with the inlet and outlet portions, respectively, for directing fluid or gas to flow through the dual spiral channel. The sensing circuitry is electrically connected with the spiral electrode pair and configured to sense the particles in the fluid or gas in accordance with an impedance of the spiral electrode pair and the fluid or gas flowing through the dual spiral channel.

Inventors

  • LIBSCH, FRANK ROBERT
  • Balagurusamy, Venkat Kanagraj

Assignees

  • International Business Machines Corporation

Dates

Publication Date
20260506
Application Date
20240610

Claims (13)

  1. 1 . An impedance sensing structure, comprising: a dielectric layer; a spiral electrode pair forming a dual spiral channel on the dielectric layer and having an inlet portion at a central region of the dual spiral channel and an outlet portion at an end of the dual spiral channel; inlet and outlet elements coupled with the inlet and outlet portions, respectively, for directing fluid or gas to flow through the dual spiral channel; and sensing circuitry electrically connected with the spiral electrode pair and configured to sense the particles in the fluid or gas in accordance with an impedance of the spiral electrode pair and the fluid or gas flowing through the dual spiral channel.
  2. 2. The impedance sensing structure according to claim 1, wherein the spiral electrode pair are at least one of spaced proportionally to a flow rate of fluid in the dual spiral channel and a particle population rate of change with flow rate per unit time.
  3. 3. The impedance sensing structure according to claim 1 , wherein the spiral electrode pair comprises multiple spiral electrodes arranged end-to-end and insulated from one another and a common spiral electrode.
  4. 4. The impedance sensing structure according to claim 1 , wherein the spiral electrode pair forms a double-dual spiral channel having dual inlet portions and dual outlet portions.
  5. 5. The impedance sensing structure according to claim 4, wherein the spiral electrode pair comprises first and second sets of multiple spiral electrodes arranged end-to-end and insulated from one another and a pair of common spiral electrodes.
  6. 6. The impedance sensing structure according to claim 1 , wherein the spiral electrode pair forms a multi-dual spiral channel having multiple inlet portions and multiple outlet portions.
  7. 7. The impedance sensing structure according to claim 11 , wherein the spiral electrode pair comprises first and second sets of multiple spiral electrodes arranged end-to-end and insulated from one another and a pair of common spiral electrodes.
  8. 8. A method of fabricating an impedance sensing structure, the method comprising: forming dual spiral channel openings in a substrate; building a spiral electrode pair in the dual spiral channel openings such that each electrode of the spiral electrode pair extends upwardly from the substrate to form a dual spiral channel having an inlet portion at a central region of the dual spiral channel and an outlet portion at an end of the dual spiral channel; coupling inlet and outlet elements with the inlet and outlet portions, respectively, for directing fluid or gas to flow through the dual spiral channel; electrically connecting sensing circuitry to the spiral electrode pair; and configuring the circuitry to sense particles in the fluid or gas in accordance with an impedance of the dual spiral channel and the fluid or gas.
  9. 9. The method according to claim 8, wherein the building of the spiral electrode pair comprises: arranging multiple spiral electrodes end-to-end; insulating the multiple spiral electrodes from one another; and configuring the multiple spiral electrodes in a spiral pattern with a common spiral electrode.
  10. 10. The method according to claim 9, wherein the building of the spiral electrode pair is executed such that the spiral electrode pair forms a double-dual spiral channel having dual inlet portions and dual outlet portions.
  11. 11 . The method according to claim 10, wherein the building of the spiral electrode pair comprises: arranging first and second sets of multiple spiral electrodes end-to-end; insulating the first and second sets of the multiple spiral electrodes from one another; and configuring the first and second sets of multiple spiral electrodes in a pair of spiral patterns with a pair of common spiral electrodes.
  12. 12. The method according to claim 8, wherein the building of the spiral electrode pair is executed such that the spiral electrode pair forms a multi-dual spiral channel having multiple inlet portions and multiple outlet portions.
  13. 13. The method according to claim 12, wherein the building of the spiral electrode pair comprises: arranging multiple sets of multiple spiral electrodes end-to-end; insulating the multiple sets of the multiple spiral electrodes from one another; and configuring the multiple sets of the multiple spiral electrodes in multiple spiral patterns with multiple common spiral electrodes.

Description

SPIRAL IMPEDANCE STRUCTURE BACKGROUND [0001] The present invention generally relates to impedance systems. More specifically, the present invention relates to a spiral impedance system structure for microelectronic sensing. [0002] Capacitively coupled contactless conductivity detection (C4D) is a detection technique that is used mainly in capillary electrophoresis and microchip electrophoresis. The characteristics of a C4D detector are generally simple in structure, easy in miniaturization and integration and free of electrode contamination, all of which are common problems in an electrochemical detection. SUMMARY [0003] Embodiments of the invention are directed to an impedance sensing structure. A non-limiting example of the impedance sensing structure includes a dielectric layer, a spiral electrode pair forming a dual spiral channel on the dielectric layer and having an inlet portion at a central region of the dual spiral channel and an outlet portion at an end of the dual spiral channel, inlet and outlet elements and sensing circuitry. The inlet and outlet elements are coupled with the inlet and outlet portions, respectively, for directing fluid or gas to flow through the dual spiral channel. The sensing circuitry is electrically connected with the spiral electrode pair and configured to sense the particles in the fluid or gas in accordance with an impedance of the spiral electrode pair and the fluid or gas flowing through the dual spiral channel. [0004] Embodiments of the present invention are directed to an impedance sensing structure for sensing particles in a fluid or gas. A non-limiting example of the impedance sensing structure includes a dielectric layer, a spiral electrode pair forming a dual spiral channel on the dielectric layer and having an inlet portion at a central region of the dual spiral channel and an outlet portion at an end of the dual spiral channel, inlet and outlet elements coupled with the inlet and outlet portions, respectively, for directing the fluid or gas to flow through the dual spiral channel and sensing circuitry electrically connected with the spiral electrode pair and configured to sense the particles in the fluid or gas in accordance with an impedance of the spiral electrode pair and the fluid or gas flowing through the dual spiral channel. [0005] Embodiments of the present invention are directed to a method of fabricating an impedance sensing structure. A non-limiting example of the method includes forming dual spiral channel openings in a substrate and building a spiral electrode pair in the dual spiral channel openings such that each electrode of the spiral electrode pair extends upwardly from the substrate to form a dual spiral channel having an inlet portion at a central region of the dual spiral channel and an outlet portion at an end of the dual spiral channel. The method further includes coupling inlet and outlet elements with the inlet and outlet portions, respectively, for directing fluid or gas to flow through the dual spiral channel, electrically connecting sensing circuitry to the spiral electrode pair and configuring the circuitry to sense particles in the fluid or gas in accordance with an impedance of the dual spiral channel and the fluid or gas. [0006] Additional technical features and benefits are realized through the techniques of the present invention. Embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed subject matter. For a better understanding, refer to the detailed description and to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0007] The specifics of the exclusive rights described herein are particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the embodiments of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: [0008] FIG. 1 is a side view of an impedance sensing structure in accordance with one or more embodiments of the present invention; [0009] FIG. 2 is a top-down view of a spiral channel of the impedance sensing structure of FIG. 1 in accordance with one or more embodiments of the present invention; [0010] FIG. 3 is a top-down view of a spiral channel with electrode sections of the impedance sensing structure of FIG. 1 in accordance with one or more embodiments of the present invention; [0011] FIG. 4 is a top-down view of a double-dual spiral channel of the impedance sensing structure of FIG. 1 in accordance with one or more embodiments of the present invention; [0012] FIG. 5 is a top-down view of multiple spiral channels with sets of multiple spiral electrodes arranged end-to- end and insulated from one another and a pair of common spiral electrodes of the impedance sensing structure of FIG. 1 in accordance with one or more embodiments of the present invention; [0013] FIG. 6 is a top-down view of a m