HUMIDITY SENSOR

• US 20110308313A1
• Filed: 06/01/2011
• Published: 12/22/2011
• Est. Priority Date: 06/17/2010
• Status: Abandoned Application

• Current Assignee: Geneasys Pty Ltd
• Original Assignee: Geneasys Pty Ltd
• Inventors: Azimi, Mehdi, Silverbrook, Kia
• Application Number:
  US13/150,242
• Publication Number:
  US 20110308313A1
• Time in Patent Office: Days
• US Class Current: 73/335.04
• CPC Class Codes: B01L 2200/10 Integrating sample preparation and analysis in single entity, e.g. lab-on-a-chip concept
• CPC Class Codes: B01L 2300/023 Sending and receiving of information, e.g. using bluetooth
• CPC Class Codes: B01L 2300/024 Storing results with means integrated into the container
• CPC Class Codes: B01L 2300/0636 Integrated biosensor, microarrays
• CPC Class Codes: B01L 2300/0654 Lenses; Optical fibres
• CPC Class Codes: B01L 2300/0883 Serpentine channels
• CPC Class Codes: B01L 2300/10 Means to control humidity and/or other gases
• CPC Class Codes: B01L 2300/1827 using resistive heater
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 2400/0633 with moving parts
• CPC Class Codes: B01L 2400/0677 phase change valves; Meltable, freezing, dissolvable plugs; Destructible barriers
• CPC Class Codes: B01L 2400/0688 surface tension valves, capillary stop, capillary break
• CPC Class Codes: B01L 3/5027 by integrated microfluidic structures, i.e. dimensions of channels and chambers are such that surface tension forces are important, e.g. lab-on-a-chip B01L3/5023 takes precedence; micromixers B01F33/30; microreactors for synthesis B01J19/0093; microcapillary devices in general B81B1/00
• CPC Class Codes: B01L 3/502707 characterised by the manufacture of the container or its components by shaping or joining plastic parts B29C59/00, B29C65/00; by laminating B32B37/00; manufacture of microstructural devices in general B81C
• CPC Class Codes: B01L 3/502738 characterised by integrated valves microvalves F16K99/0001
• CPC Class Codes: B01L 7/52 with provision for submitting samples to a predetermined sequence of different temperatures, e.g. for treating nucleic acid samples amplification or hybridisation processes per se C12Q1/68; controlling sequential reactions for synthesis B01J19/0046
• CPC Class Codes: C12Q 1/68 involving nucleic acids
• CPC Class Codes: F16K 99/003 Valves for single use only
• CPC Class Codes: F16K 99/0036 operated by temperature variations
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
• CPC Class Codes: Y10T 137/0352 : Controlled by pressure
• CPC Class Codes: Y10T 137/0391 : Affecting flow by the addition of material or energy
• CPC Class Codes: Y10T 137/1044 : With other condition responsive valve control
• CPC Class Codes: Y10T 137/206 : Flow affected by fluid contact, energy field or coanda effect [e.g., pure fluid device or system]
• CPC Class Codes: Y10T 137/2076 : Utilizing diverse fluids
• CPC Class Codes: Y10T 137/2202 : By movable element
• CPC Class Codes: Y10T 436/107497 : Preparation composition [e.g., lysing or precipitation, etc.]
• CPC Class Codes: Y10T 436/11 : Automated chemical analysis
• CPC Class Codes: Y10T 436/143333 : Saccharide [e.g., DNA, etc.]
• CPC Class Codes: Y10T 436/145555 : Hetero-N
• CPC Class Codes: Y10T 436/173845 : Amine and quaternary ammonium
• CPC Class Codes: Y10T 436/203332 : Hydroxyl containing
• CPC Class Codes: Y10T 436/25 : including sample preparation
• CPC Class Codes: Y10T 436/25375 : Liberation or purification of sample or separation of material from a sample [e.g., filtering, centrifuging, etc.]

Abstract

A humidity sensor having a pair of electrodes spaced adjacent each other and defining an air gap therebetween such that the electrodes provide a capacitor with air as dielectric material, and, circuitry for sensing capacitance connected to the electrodes such that changes in permittivity of the air in the air gap caused by changes in humidity, cause changes in capacitance, wherein, the circuitry generates a signal indicative of humidity in the air in response to sensed capacitance of the electrodes.

Claims

1. A humidity sensor comprising:

a pair of electrodes spaced adjacent each other and defining an air gap therebetween such that the electrodes provide a capacitor with air as dielectric material; and

,

circuitry for sensing capacitance connected to the electrodes such that changes in permittivity of the air in the air gap caused by changes in humidity, cause changes in capacitance;

wherein,

the circuitry generates a signal indicative of humidity in the air in response to sensed capacitance of the electrodes.

2. The humidity sensor according to claim 1 wherein the electrodes each have a comb-like structure with their respective teeth extending towards each other, and interleaved with each other such that the air gap has a serpentine shape.

3. The humidity sensor according to claim 2 wherein the electrodes are defined in a layer of conductive material supported on a substrate and lithographically etched to provide the comb-like structures.

4. The humidity sensor according to claim 3 wherein the conductive material is titanium nitride and the substrate is a planar surface on a LOC (lab-on-a-chip) device.

5. The humidity sensor according to claim 4 wherein the circuitry is CMOS circuitry on the LOC device.