Thin film sensor
An electrically operated, particle detecting, or characterizing, sensor structured as a thin film multilayer sandwich. Three or more electrodes are deposited onto thin layers of film, and stacked to form the sandwich. A representative stacking arrangement provides a pair of stimulated electrodes spaced apart from an intermediate measurement electrode by insulating layers of thin film. A fluid conducting channel, having an axis perpendicular to the film layers, provides electrolytic electrical communication between the three electrodes. Contact pads, arranged to permit electrical interrogation of the electrodes by electrical circuitry, are desirably arranged for access to electrical interrogation probes from a single side of the sensor. Certain sensors may be included in single-use, disposable cartridges adapted for analysis by an interrogation platform.
1. A method for analyzing particles suspended in a fluid, comprising the steps of:
adding a volume of particle-containing fluid to a one-time use disposable cartridge comprising a thin film sensor structured to provide at least one fluid-flow channel formed between layers of said sensor, a portion of said at least one fluid-flow channel having side walls comprising a through-the-thickness cut-out from a channel layer, said side walls being capped by other layers to form a perimeter boundary around said portion though which fluid may be urged to flow past an electrode and along a local length axis;
causing a pressure differential across said thin-film sensor effective to move said fluid through said sensor; and
analyzing particles flowing through said sensor by monitoring changes in electric impedance at said electrode as said particles flow through one or more interrogation channels.
2. The method according to claim 1 , further comprising the step of:
inserting said cartridge into a docking port of an interrogation platform prior to causing said pressure differential.
3. The method according to claim 1 , further comprising the step of:
displaying analysis results on a display screen of said interrogation platform.
4. The method according to claim 1 , wherein:
said thin film sensor comprises a plurality of hydraulically parallel interrogation zones, each such interrogation zone being structured and arranged to electrically detect particles entrained in said fluid and passing through said zone; and
particles moving through said parallel interrogation zones are analyzed in parallel.
5. The method according to claim 1 , wherein:
said volume is a known volume.
6. The method according to claim 1 , wherein:
said thin film sensor comprises a first stimulated electrode providing an area disposed in a substantially planar configuration;
a first measurement electrode providing an area disposed in approximately parallel proximity to said first stimulated electrode;
a second stimulated electrode providing an area disposed in approximately parallel proximity to said first measurement electrode, and on an opposite side of said first measurement electrode from said first stimulated electrode;
a first electrically insulating layer disposed between said first stimulated electrode and said first measurement electrode to resist electrical communication there-between;
a second electrically insulating layer disposed between said first measurement electrode and said second stimulated electrode to resist electrical communication there-between; and
a first channel providing a fluid flow path permitting fluid flowing therein to contact a portion of each of:
said first stimulated electrode;
said first insulating layer;
said first measurement electrode;
said second insulating layer; and
said second stimulated electrode; such that
an electrolyte disposed in said channel permits electrical communication between said first stimulated electrode, said first measurement electrode, and said second stimulated electrode; and wherein:
a top surface of said first measurement electrode is affixed to a bottom surface of said first insulating layer and a bottom surface of said first measurement electrode is affixed to a top surface of said second insulating layer.
7. The method according to claim 6 , wherein:
said channel passes through said measurement electrode.
8. An electrically operated sensor including a thin film arrangement structured as a multilayer sandwich, the sensor comprising:
a first stimulated electrode providing an area disposed in a substantially planar configuration;
a first measurement electrode providing an area disposed in approximately parallel proximity to said first stimulated electrode;
a second stimulated electrode providing an area disposed in approximately parallel proximity to said first measurement electrode, and on an opposite side of said first measurement electrode from said first stimulated electrode;
a first electrically insulating layer disposed between said first stimulated electrode and said first measurement electrode to resist electrical communication there-between;
a second electrically insulating layer disposed between said first measurement electrode and said second stimulated electrode to resist electrical communication there-between; and
a first channel providing a fluid flow path permitting fluid confined therein to contact a portion of said first stimulated electrode, a portion of said first insulating layer, a portion of said first measurement electrode, a portion of said second insulating layer, and a portion of said second stimulated electrode, and permitting electrolytic electrical communication between said first stimulated electrode, said first measurement electrode, and said second stimulated electrode; wherein:
a top surface of said first measurement electrode is disposed in contact with a bottom surface of said first insulating layer and a bottom surface of said first measurement electrode is disposed in contact with a top surface of said second insulating layer.
9. The method according to claim 8 , wherein:
said channel passes through said measurement electrode.
10. An electrically operated sensor including a thin film arrangement structured as a multilayer sandwich, the sensor comprising:
a first stimulated electrode providing an area disposed in a substantially planar configuration;
a first measurement electrode providing an area disposed in approximately parallel proximity to said first stimulated electrode;
a second stimulated electrode providing an area disposed in approximately parallel proximity to said first measurement electrode, and on an opposite side of said first measurement electrode from said first stimulated electrode;
a first electrically insulating layer disposed between said first stimulated electrode and said first measurement electrode to resist electrical communication there-between;
a second electrically insulating layer disposed between said first measurement electrode and said second stimulated electrode to resist electrical communication there-between; and
a first channel providing a fluid flow path permitting fluid confined therein to contact a portion of said first stimulated electrode, a portion of said first insulating layer, a portion of said first measurement electrode, a portion of said second insulating layer, and a portion of said second stimulated electrode, and permitting electrolytic electrical communication between said first stimulated electrode, said first measurement electrode, and said second stimulated electrode; wherein:
a top surface of said first measurement electrode is affixed to a bottom surface of said first insulating layer and a bottom surface of said first measurement electrode is affixed to a top surface of said second insulating layer.
11. The method according to claim 10 , wherein:
said channel passes through said measurement electrode.