Interferometric Chemical Sensor Array

• US 20090316158A1
• Filed: 06/22/2009
• Published: 12/24/2009
• Est. Priority Date: 06/23/2008
• 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: Ash, William M. III
• Granted Patent: US 8,269,974 B2
• Time in Patent Office: Days
• US Class Current: 356/450
• CPC Class Codes: G01B 9/02023 Indirect probing of object, e.g. via influence on cavity or fibre
• CPC Class Codes: G01B 9/02051 Integrated design, e.g. on-chip or monolithic
• CPC Class Codes: G01N 21/45 using interferometric methods; using Schlieren methods
• CPC Class Codes: G02B 2006/12097 Ridge, rib or the like
• CPC Class Codes: G02B 2006/12104 Mirror; Reflectors or the like
• CPC Class Codes: G02B 2006/12138 Sensor
• CPC Class Codes: G02B 6/12007 forming wavelength selective elements, e.g. multiplexer, demultiplexer
• CPC Class Codes: G02B 6/2935 Mach-Zehnder configuration, i.e. comprising separate splitting and combining means
• CPC Class Codes: G02B 6/29395 configurable, e.g. tunable or reconfigurable switching G02B6/35

Abstract

The device is a gas/vapor/aerosol/particulate sensor with a receiver/transmitter option. This optical MEMS device is designed to be a self-contained optical bench, integrating of an entire interferometer into a MOEMS ‘optical bench’ system-on-a-chip, and includes multiplexed optical path sensors. The sensing structures consist of laser sources, semiconductor photo detectors, refractive/reflective optical elements, and specialized optical transmission paths. Each individual laser source and photodiode is an optical path sensor with a particular ‘functionalization.’ These sensing arm functionalizations are sensitive to unique chemical signatures and as a result can recognize and report various chemical agents present in the ambient environment.

Claims

1. ) An interferometric, single chip sensor comprising:

a laser;

a first optical path having a functionalized sense arm open to an ambient environment, the sense arm reactive to a preselected chemical signature;

a second optical path having a reference arm sealed from the ambient environment;

a beam splitter sending light emitted from the laser to both the first and second optical paths whereby the chemical signature reacting at the functional sense arm changes the first optical path length relative to the second optical path length;

a beam recombiner creating a superposition of sense and reference beams yielding interference fringes responsive to the change in the first optical path length; and

a photodetector for converting the interference fringes into a detectable electrical signal.

2. ) The sensor of claim 1 wherein the sense arm is reactive to a plurality of chemical signatures.

3. ) The sensor of claim 1 wherein the sensing functionalization of the sense arm is selected from the group consisting of nanowires, aerogels, aero-corals, crystal matrices, particulate meshes, catalyst meshes, amorphous materials and treated fabrics.

4. ) The sensor of claim 1 wherein the functionalized sense arm further comprises chemically reactive nanostructures open to the ambient environment and the reference arm further comprises chemically reactive nanostructures sealed from the ambient environment.

5. ) The sensor of claim 1 further comprising a wireless transmitter communicatively coupled to the photodetector, the wireless transmitter broadcasting data responsive to a predetermined value of the detectable electrical signal converted by the photodetector.

6. ) A chemical vapor sensor array comprising:

a plurality of interferometric sensors on a single chip, each sensor specific to a preselected chemical signature, each sensor comprising;

a laser;

a first optical path having a functionalized sense arm open to an ambient environment and reactive to the preselected chemical signature;

a second optical path having a reference arm sealed from the ambient environment;

a beam splitter sending light emitted from the laser to both the first and second optical paths whereby the chemical signature reacting at the functional sense arm changes the first optical path length relative to the second optical path length;

a beam recombiner creating a superposition of sense and reference beams yielding interference fringes responsive to the change in the first optical path length; and

a photodetector for converting the interference fringes into a detectable electrical signal,

whereby the identity of the chemical vapor is logically derived by one or more electrical signals from the sensors.

7. ) The array of claim 6 further comprising a logic gate integral to the chip, the logic gate activating a signal responsive to an identification of the chemical vapor.

8. ) The array of claim 6 further comprising a wireless transmitter to forward the one or more electrical signals from the sensors to a remote logic processor for deriving the identity of the chemical vapor.

9. ) The array of claim 7 further comprising a wireless transmitter to forward the signal to a remote receiver.

10. ) The array of claim 6 wherein the sense arm of at least one sensor on the array is reactive to a plurality of chemical signatures.

11. ) The array of claim 6 wherein the chemical vapor sensor array is a single use device whereby upon detection the electrical signals received from the sensors the state of the electrical signals is maintained.

12. ) A chemical vapor sensor array comprising:

a plurality of interferometric sensors on a single chip, each sensor specific to at least one preselected chemical signature to collectively identify a chemical vapor, each sensor comprising;

a laser;

a first optical path having a functionalized sense arm open to an ambient environment and reactive to a sensor-specific preselected chemical signature;

a second optical path having a reference arm sealed from the ambient environment;

a beam splitter sending light emitted from the laser to both the first and second optical paths whereby the chemical signature reacting at the functional sense arm changes the first optical path length relative to the second optical path length;

a beam recombiner creating a superposition of sense and reference beams yielding interference fringes responsive to the change in the first optical path length; and

a photodetector for converting the interference fringes into a detectable electrical signal;

a logic gate integral to the chip, the logic gate deriving the identity of the chemical vapor by one or more electrical signals from the sensor, the logic gate subsequently activating a signal responsive to an identification of the chemical vapor.

13. ) A chemical vapor sensor array comprising:

a plurality of interferometric sensors on a single chip, each sensor specific to a unique preselected chemical signature, each sensor comprising;

a laser;

a first optical path having a functionalized sense arm open to an ambient environment and reactive to the sensor'"'"'s unique preselected chemical signature;

a second optical path having a reference arm sealed from the ambient environment;

a beam splitter sending light emitted from the laser to both the first and second optical paths whereby the chemical signature reacting at the functional sense arm changes the first optical path length relative to the second optical path length;

a beam recombiner creating a superposition of sense and reference beams yielding interference fringes responsive to the change in the first optical path length; and

a photodetector for converting the interference fringes into a detectable electrical signal,

whereby the identity of the chemical vapor is logically derived by one or more electrical signals from the sensors against an empirically establish matrix of known chemical vapor signal patterns.