The present invention is carried out with governmental support, and part is studied by Environmental hygienic scienceBeing subsidized, license number is 1R01ES016569-01A1.Government has some power in the present inventionProfit.
Detailed description of the invention
Presently disclosed embodiment provides the temperature independent methodology for selectivity steam sensingAnd system, the most single sensor is provided and can detect and individually or each other existsIn the case of multiple steam and/or the mixture of steam.At entitled " Highly SelectiveChemical and Biological Sensors " U.S. patent application serial number 12/942,732In describe for using single sensor to carry out the example of conventional method of steam sensing, pass throughQuote and be incorporated into herein.Disclosed sensor even under high humidity environment orWherein one or more steam have much higher concentration (example compared with other composition in mixtureAs, 10 times) in the environment of also be able to the detection different steam in the presence of variable temperatureAnd mixture.Each sensor includes the resonant inductor-capacitor-resistance being coated with sensing materialDevice (LCR) sensor.The temperature relevant response coefficient of the character of LCR circuit and sensing material thatThese are different.The difference of the temperature relevant response coefficient of character affects the measurement of disclosed sensor.ButIt is about the knowledge of temperature relevant response coefficient of character and/or how to be subject to about sensorThe knowledge of the difference impact of the temperature relevant response coefficient of character starves impedance together with the measurement of sensorMultivariate analysis be used together, in order to provide temperature unrelated selectivity steam sensing and improveResponse stability.Such as, the lookup of the coefficient including sensor-based experiment test can be formedTable.During the use of sensor, the coefficient that experiment determines can be for examining in multivariate analysisThe change of the temperature during worry sensing.Other embodiments disclosed herein provides for selectivityChemistry and the temperature independent methodology of biological sensing and system, the most single sensor be provided andIn the case of can detecting individually or there is (presense of one another) each otherChemistry or the liquid of biological species and/or mixture in multiple chemistry or biological species.
The non-limiting example of LCR sensor includes having integrated circuit (IC) memory chipRFID sensor, there is the RFID sensor of IC chip and there is no IC memory chipRFID sensor (chipless RFID sensor).LCR sensor can be wirelessly or non-wirelessly.In order to collect data, the resonant frequency range of narrower frequency range, such as LCR circuit is obtainedTake impedance spectrum.This technology also includes from acquired spectrum to calculate multivariate signature, and manipulation shouldData are to differentiate the existence of some steam and/or vapour mixture.The existence of steam is by followingStep detects: by the change of resonant electrical character of observation circuit, measure dielectric, dimension,Change in electric charge transfer and other change of the character of employing material.By using mathematics mistakeJourney, such as principal component analysis (PCA) etc., multiple steam and mixture can be in the feelings existed each otherIt is detected, as described further below under condition and in the presence of chaff interference.HereinThe disclosed embodiments provide the temperature independent methodology for selectivity fluid sensing and system, itsIn single sensor be provided and can detect individually or each other in the presence ofMultiple fluids and/or the mixture of fluid.Further embodiment is open for through the following stepsThe method manufacturing this kind of sensor: assemble the transducer including LCR circuit, and will sensingMaterial be arranged on transducer at least some of on, wherein transducer and the character of sensing materialTemperature relevant response coefficient different from each other.In other embodiments, except for steam and streamOutside the chemical sensor of body, biosensor also can have temperature extraneous detection ability.
In order to become apparent from describing exactly the theme of claimed invention, it is provided that be described belowWith being defined below of the concrete term used in claims.
Term " fluid " includes gas, steam, liquid, particle, biomone, biology pointSon and solid.
Term " numeral ID " includes all numbers stored in the memory chip of RFID sensorAccording to.The non-limiting example of these data is the manufacturer for sensor, electronics pedigree(pedigree) data, user data and calibration data.
Term " monitoring process " includes but not limited to measure the physical change occurred around sensor.Such as, monitoring process includes the physics of environment around monitoring and sensor, chemistry and/or lifeBio-pharmaceuticals that the change of physical property matter is relevant, the change of Foods or drinks manufacture process.MonitoredJourney may also include those industry of the change of monitoring physical change and the composition of composition or positionProcess.Non-limiting example include national security monitoring, residential quarter monitoring for protection, environmental monitoring,Clinic or bedside patient's monitoring, airport security monitoring, admission ticket checking and other public accident.EnergyReach when sensor signal has reached slightly steady-state response and/or sensor has dynamic responseShi Zhihang monitors.Steady state sensor response be determined by the time cycle from the sound of sensorShould, wherein respond and there is no change slightly in the measurement time.Therefore, steady state sensor response withThe measurement of time produces similar value.Dynamic pickup response be measured ambient parameter (temperature,Pressure, chemical concentrations, biological concentration etc.) change time from the response of sensor.Therefore,Time significant change is being measured in dynamic pickup response, in order to produce measured one or manyThe dynamic signature of the response of individual ambient parameter.The non-limiting example of the dynamic signature of response includesThe maximal positive slope of average response slope, average response amplitude, signal response, signal respondMaximum negative slope, the mean change of signal response, the maximum of signal response are just changing and signalThe negative change of the maximum of response.The dynamic signature of the generation of response can be used in further enhancing at listThe solely selectivity of the sensor in the kinetic measurement of steam and mixture thereof.Being produced of response is dynamicState signature can also be used to optimize sensing material and the combination of transducer geometry further, withJust strengthen in independent steam and the selection of the sensor dynamically and in steady state measurement of mixture thereofProperty.
Term " ambient parameter " is for representing measuring among manufacture or monitoring system or aroundEnvironmental variable.Measure environment variables can include at least one in physics, chemistry and biological property,And include but not limited to temperature, pressure, material concentration, conductivity, dielectric property, sensingNear device or with the quantity of electrolyte, metal, chemistry or the biomone of sensor contacts,The dosage of ionizing irradiation and the measurement of light intensity.
Term " analyte " includes that ambient parameter is measured in any expection.
Term " disturbs " precision and accuracy including undesirably affecting the measurement of sensorAny undesirable ambient parameter.Term " chaff interference " expression can be produced by sensor potentiallyThe fluid of raw disturbance response or ambient parameter (including but not limited to temperature, pressure, light etc.).
Term " multivariate analysis " represents for analyzing more than one variable from sensor responseAnd provide the type with at least one ambient parameter from measured sensor spectra parameter to haveThe information closed and/or the water of at least one ambient parameter with next self-metering sensor spectra parameterThe mathematical procedure of flat relevant quantitative information.Term " principal component analysis (PCA) " expression is used forCube is reduced to more low-dimensional for the mathematical procedure analyzed.Principal component analysis is multivariateA part for the Eigenanalysis method of the statistical analysis of data, and can use covariance matrix orCorrelation matrix performs.The non-limiting example of multivariate analysis tools includes relevant point of canonicalAnalysis, regression analysis, nonlinear regression analysis, principal component analysis, distinctive function analysis, multidimensionalCalibration, linear discriminatant analysis, logarithm regression or analysis of neural network.
Term " spectrum parameter " is for representing the measurable variable that sensor responds.Sensor respondsIt it is the impedance spectrum of the resonance sensor circuit of LCR or RFID sensor.Z is taked except measuringOutside the impedance spectrum of parameter, S parameter and other parametric form, impedance spectrum (its real part and imaginary partBoth) can use and analyze for the many kinds of parameters analyzed simultaneously, the maximum of the real part of such as impedanceFrequency (the F of numberP), the amplitude (Z of the real part of impedanceP), the resonant frequency (F of the imaginary part of impedance1)Anti-resonance frequency (F with the imaginary part of impedance2), at the resonant frequency (F of imaginary part of impedance1) letterNumber amplitude (Z1), at the anti-resonance frequency (F of imaginary part of impedance2) signal amplitude (Z2) and zeroReactance frequency (Fz, the imaginary part of impedance is the frequency of zero).Other spectrum parameter can use whole impedanceThe amplitude of spectrum, the factor of quality of such as resonance, phase angle and impedance is measured simultaneously.From impedance" spectrum parameter " that spectrum is calculated here is referred to as " feature " or " descriptor ".From canThe all potential feature calculated by spectrum is to perform the suitable selection of feature.EntitledThe U.S. of " Methods and systems for calibration of RFID sensors "State's patent application serial number 12/118, describes multivariate spectrum parameter, by quoting it in 950It is incorporated herein in.
Term " resonance impedance " or " impedance " represent extracts sensor " spectrum parameter " from whichSensor resonance around measurement sensor frequency response.
Term " protection material " includes but not limited to protection sensing in LCR or RFID sensorDevice performs anticipated measurement from non-anticipated machinery, physically or chemically effect, the most still allowanceMaterial.Such as, it is contemplated that measuring and can include that solution conductivity rate is measured, wherein protecting film is by sensorSeparate with liquid solution, but still allow for electromagnetic field and penetrate in solution.One example of protection materialIt is consequently exerted at above sensor to protect the sensor against the paper membrane of mechanical failure and abrasion.ProtectionAnother non-limiting example of material is consequently exerted at above sensor and is putting with protection sensorEnter the polymeric film from corrosion when measuring in liquid.Protection material can also be consequently exerted atTime above sensor to prevent the antenna circuit of sensor from measuring in putting into conducting liquidThe polymeric film of short circuit.The non-limiting example of protecting film is paper, polymerization and inoranic membrane, such asPolyester, polypropylene, polyethylene, polyethers, Merlon, polyethylene terephthalate,Zeolite, metallic organic framework and cryptand (cavitand).Protection material can be arranged on and changeCan be between device and sensing film, in order to protection transducer.Protection material can be arranged on and itself be inAbove sensing film above transducer, in order to protection sensing film and transducer.Itself is in transducingThe protection material above sensing film above device can act as filtering material, in order to prevents from sensing filmIt is exposed to gas or ion interference.The non-limiting example of filtering material includes that zeolite, metal haveMachine skeleton and cryptand.
Term as used herein " sensing material and sensing film " includes but not limited to deposit to changeCan device electronic module, as in LCR circuit assembly or RFID label tag in case perform with environmentTime mutual measurable and reproducibly affect the material of the function that impedance transducer responds.ExampleAs, the conducting polymer of such as polyaniline etc changes it when being exposed to the solution of different pHConductivity.When this polyaniline film deposits on LCR or RFID sensor, impedance sensingDevice response changes as the function of pH.Therefore, this LCR or RFID sensor conductPH sensor is operated.When this polyaniline film deposits to supply on LCR or RFID sensorDuring detection in gas phase, impedance transducer response is being exposed to alkalescence (such as, NH3) or acidAlso change during (such as, HCl) gas.Alternatively, sensing film can be dielectric polymer.Sensor film includes but not limited to that environment based on they places changes its electric and/or dielectricThe polymer of character, organic and inorganic, biological, synthesis and nanometer synthesis film.Sensor filmNon-limiting additional examples can be such as Nafion (Nafion) etcThe adhesive polymer of sulfonated polymer, such as silicone adhesive etc, such as sol gel film etcInoranic membrane, the synthesis film of such as carbon black polyisobutylene sheet etc, such as CNT-high fluorineChange ion exchange resin membrane, golden nanometer particle polymeric film, metal nanoparticle polymeric film,Static Spinning polymer nanofiber, Static Spinning inorganic nano-fiber, Static Spinning synthesis nanofiberEtc nanometer synthesis film or doped with organic, metal is organic or the film of biologically-derived molecule/ fiber and other sensing material any.In order to prevent the material in sensor film from leaching into liquidIn body environment, use standard technique and this area of such as covalency joint, electrostatic joint etcSensing material is attached to sensor surface by other standard technique known to the skilled person.It addition,Sensing material has the temperature associated change phase of the material dielectric constant with sensing material and resistanceAt least two temperature relevant response coefficient closed.
Term " transducer and sensor " for represent estimate for sensing electronic installation, asRFID device." transducer " is before being coated with sensing or protecting film or calibratedFor the device before sensing application.Transducer includes the electric capacity C of LCR circuit, resistance RAt least three temperature relevant response coefficient with the temperature associated change of inductance L." sensor "It is that typically in after being coated with sensing or protecting film and calibrated for sensing applicationAfter device.
Term as used herein " RFID label tag " represent electronic tag is used for mark and/orFollowing the tracks of RFID label tag can be with the mark of its attached product and reporting techniques.RFID label tag is usualIncluding at least two assembly, wherein the first assembly is for storing and process information and to radio frequencyIntegrated circuit (IC) memory chip that signal is modulated and demodulates.This memory chip is alsoCan be used in other dedicated functions, such as it can comprise capacitor.It can also comprise simulationAt least one input of signal, such as resistance input, electric capacity input or inductance input.At centrelessIn the case of sheet RFID label tag, RFID label tag can not include IC memory chip.NotNeed to identify particular RFID tag but the signal of the only existence of indicating label offer useful informationIn the application of (such as, product safety is applied), such RFID label tag can be useful.Second assembly of RFID label tag is the antenna for receiving and transmit radiofrequency signal.
Term " RFID sensor " is the RFID label tag of the sensing function with increase, its exampleAs changed its impedance parameter also by the function as environmental change when the antenna of RFID label tagPerform sensing function.Use this kind of RFID sensor that accurately determining of environmental change is passed throughAnalyze resonance impedance to perform.Such as, can be by using sensing film coating RFID label tag, willRFID label tag is converted to RFID sensor.By using sensing film to apply RFID label tag,The electroresponse of film is converted to the impedance response to sensor antenna, and the impedance of sensor antenna ringsResonance peak position, spike width, peak height and the peak symmetry answered, the real part of impedanceAmplitude, the resonant frequency of imaginary part of impedance, the anti-resonance frequency of imaginary part of impedance, zero reactanceThe amplitude of frequency, phase angle and impedance and in the definition of term sensor " spectrum parameter "Change while other parameter described." RFID sensor " can have and be attached to antennaIntegrated circuit (IC) memory chip, or without IC memory chip.There is no ICThe RFID sensor of memory chip is LCR sensor.LCR sensor is by forming LCR electricitySuch as at least one inducer (L) on road, at least one capacitor (C) and at least one resistorEtc (R) known tip assemblies composition.
Term " disposable container " includes but not limited to be dropped after usage or can be throughCross and overhaul the manufacture or monitoring device and packaging Gong re-using.The non-returnable container bag of food service industryInclude but be not limited to Food & Drink packaging and confection and tuck box.Disposable monitoring assembly bagInclude but be not limited to disposable cartridges (cartridge), radiacmeter and catcher.Disposably manufacture appearanceDevice includes but not limited to disposable vessel, bag, case, pipeline, adapter and pillar.
Term " write device/reader " includes but not limited to write data into and read in memorizerThe combination of the device of the memorizer of chip and the impedance of reading antenna." write device/reader "Another term be " interrogator ".
According to embodiment disclosed herein, describe and be used for sensing steam, vapour mixture, chemistryLCR or RFID sensor with biological species.As it was previously stated, RFID sensor includes coatingThere is the RFID mark of the sensing material of the temperature relevant response coefficient of the character different from LCR circuitSign.In one embodiment, passive RFID tags can be used.Everybody can be appreciated that, RFIDLabel can include being connected the IC storage for communicating with write device/reader with aerial coilDevice chip.Can be carried by the radio frequency (RF) sent via write device/reader and/or microwaveRipple signal irradiates label, reads IC memory chip.When RF and/or microwave field are through skyDuring line coil, coil produces AC voltage.To this voltage commutation in microchip, in order toProduce the D/C voltage for microchip operation.IC memory chip reaches predetermined electricity in D/C voltageFunction at ordinary times.By detection from the backward scattered RF of microchip and/or microwave signal,The information of storage in microchip can be identified completely.RFID label tag/sensor and write device/readingTake distance between device by include operating frequency, RF and/or microwave power level, reader/The receiving sensitivity of write device, antenna dimension, data rate, communication protocol and microchip powerThe design parameter required manages.There is no " RFID sensor " (nothing of IC memory chipChip RFID sensor or LCR sensor or LCR transducer) and sensor reader betweenDistance is by including the reception spirit of operating frequency, RF or microwave power level, sensor readerThe design parameter of sensitivity and antenna dimension manages.
In one embodiment, the passive RFID with and without IC memory chip can be usedLabel.Advantageously, passive RFID tags operates not against battery.But, write device/Communication distance between reader and RFID label tag is typically limited within distance, becausePassive label operates only with the several microwatt RF power from write device/reader.ForIt is operated in the passive label of 13.56MHz, reads distance typically not greater than several centimeters.13.56The exemplary frequency range of the operation that MHz passive RFID tags carries out numeral ID write/reading isFrom 13.553 to 13.567MHz.13.56MHz passive RFID sensors sensing RFID passesThe exemplary frequency range of the operation of the environmental change around sensor is to about from about 5MHz20MHz, more preferably from 10 to 15MHz.The requirement of this frequency range is to adoptLabel is identified, simultaneously RFID label tag with the write device/reader being operated in 13.56MHzSensor section operates from 5 to 20MHz.
Deposit to sensing film on passive RFID tags, create RFID chemistry or biosensor.By measuring the impedance of the RFID sensor of the function as the environmental change around sensorChange, performs RFID sensing, as described further below.If the frequency of aerial coilRate response is not above the frequency range of the operation of label, then microchip after deposition sensing filmThe information of middle storage can use conventional RFID writer/reader to identify.Impedance analyzer(sensor reader) can the impedance of reading antenna coil, in order to by emerging with sense for the change of impedanceInterest chemistry is relevant with biological species, and corrects the temperature instability around sensor.
In operation, after using chemical-sensitive film coating RFID label tag, label can be measuredThe impedance of antenna and digital label ID.The digital ID measured provides and label itself, exampleIdentification and character (the such as different condition of sensor such as this label and its attached objectCalibration curve, Fabrication parameter, due date etc.) relevant information.Multicomponent is detected,Can determine that real part and many individual characteies of imaginary part of the measurement of impedance from single RFID sensorMatter, as described further below.
In a word, and according to embodiment as herein described, in order to realize changing existence in temperatureIn the case of the detection of analyte, sensor should present multiple characteristic.First, selected transducingDevice should include that multivariate exports, in order to the independent detection varying environment parameter shadow to sensorRing.Secondly, sensing material should have the response in large-scale variations in temperature to analyteThe amplitude of preservation.Response to less analyte concentration should be incomplete by bigger variations in temperatureSuppression.3rd, the temperature impact response of sensing material and transducer is to allow, but shouldIn the multivariate of transducer exports the different directions of response.
In order to realize these characteristics, in one embodiment, sensing material has steam manyIndividual response mechanism, wherein, these response mechanisms and the dielectric constant of sensing material, resistance and swollenSwollen change is correlated with, and wherein these changes are not the most perfectly correlated, and is exposingDifferent mode is produced when independent steam and mixture thereof.Additionally, LCR transducer can haveThe multiple components responded from the LCR of LCR circuit, wherein these multiple components of LCR responseBeing derived from the different factors affecting converter circuitry, it includes material resistance as non-limiting exampleAnd contact resistance between electric capacity, transducer and sensing material and electric capacity and transducer substrate withResistance between sensing material and electric capacity.Additionally, LCR transducer can have LCR circuit behaviourThe multiple conditions made, wherein IC chip is a part for sensor circuit.
Therefore, a kind of method for controlling the response of temperature correction sensor relates to integrated circuitChip power supply, in order to affect impedance spectrum section.Different impedance spectrum sections based on from different steam withAnd the temperature related sensor that changes alternately of chemistry and biological species responds.On resonant antennaIC chip or IC memory chip comprise rectifier diodes, and can be with different capacity levelIt is powered, in order to affect the impedance spectrum section of sensor.In the spectrum section of different capacity levelDifference at FP、F1、F2、FZ、ZP、Z1、Z2Different value and C and R calculating value inIt is significant.In one embodiment, by suitably selecting IC chip or IC memory chipAt least one power stage of operation realizes the unrelated sensor performance of temperature strengthened.At anotherIn embodiment, by suitably selecting IC chip or at least two merit of IC memory chip operationRate level, and analyze the combined impedance spectrum section of sensor under different capacity level, realize increasingThe unrelated sensor performance of strong temperature.Perform between relatively low and higher-wattage according to over-over modeBy at least two power stage to sensor power.In the dynamic change than measured ambient parameterWill soon at least 5 times time put on execution by least two power stage to sensor interleaved power.In all these embodiments, it is powered being in from-50dBm to+40 with different capacity levelWithin the scope of dBm, and provide the ability realizing the unrelated sensor performance of temperature.
By the operation power of change IC chip to strengthen temperature relevant response, provideThe temperature unrelated LCR circuit operation improved.Specifically, with the IC chip of sensorAt least two power stage of operation perform the pick up calibration of temperature independent operations.SensorFirst being operated in lower slightly power, therefore IC chip disconnects that (power is in about substantiallyBetween-50dBm to-10dBm), and determine in the case of analyte exists and be non-existentTransducer and the temperature correlation coefficient of sensing material.Subsequently, working sensor at slightly higher power,Therefore IC chip connects (power is between about-10dBm to+40dBm) substantially,And in the case of analyte exists and be non-existent, determine the temperature of transducer and sensing materialCorrelation coefficient.
Refer now to accompanying drawing, and with initial reference to Fig. 1, it is provided that sensing system 10, in order to illustrate utilizationThe temperature unrelated selectivity steaming that the RFID sensor 12 of sensing material 14 is carried out it is coated with on itThe principle of vapour sensing.Sensing material 14 has at least two temperature of dielectric constant and electrical resistance propertyDegree relevant response coefficient.Referring briefly to Fig. 2, sensor 12 is to include being coated with sensing materialThe resonance circuit of the Inductor-Capacitor-resistor structure (LCR) of material 14.LCR structure includesAt least three temperature relevant response of the character of the inductance L of LCR circuit, electric capacity C and resistance RCoefficient.At least three temperature relevant response coefficient of the character of LCR circuit differs the biggest each otherAbout 5%.It addition, at least two temperature relevant response coefficient of the character of sensing material 14 and LCRAt least three temperature relevant response coefficient difference at least about 5% of the character of circuit.Will sensingMaterial 14 is applied on the sensing area between electrode, and electrode forms sensor antenna 18, theyConstitute resonance circuit.As will be described further below, by sensing material 14 is applied toOn resonance circuit, the impedance response of circuit will be changed.Sensor 12 can be wired sensorOr wireless senser.Sensor 12 may also include the memory chip being coupled to resonant antenna 1816, wherein resonant antenna 18 is coupled to substrate 20.Memory chip 16 can include depositing on itManufaturing data, user data, calibration data and/or other data of storage.Memory chip 16It is IC apparatus, and includes using complementary metal oxide semiconductors (CMOS) (CMOS) process instituteThe RF signal modulation circuit manufactured and nonvolatile memory.RF signal modulation circuit assemblyIncluding diode rectifier, supply voltage control, manipulator, demodulator, clock generator andOther assembly.
Fig. 3 illustrates by an alternative of the sensor 12 represented by reference number 21, itsInclude that the supplementary sensor 23 of sensing material 14 is attached and stride across antenna 18 and integrated circuit (IC)Memory chip 16, in order to change sensor impedance response.(do not show in another embodimentGo out), supplementary sensor is attached across the antenna not having IC memory chip, and changes biographySensor impedance response.The non-limiting example of supplementary sensor is sensor intersected with each other, resistanceSensor and capacitance sensor.At entitled " Methods and systems forCalibration of RFID sensors " U.S. patent application serial number 12/118,950 inDescribe supplementary sensor, be incorporated into herein by quoting.
In one embodiment, 13.56MHz RFID label tag can be used.At sensing system 10Operation during, impedance Z (f) and the memory chip 16 of sensor antenna 18 can be obtainedThe digital sensor calibration parameter of upper storage.Referring again to Fig. 1, the resonance impedance of antenna 18The measurement of Z (f) and from memory chip 16 numerical data read/write viaMutual Inductance Coupling between the pick-up winding 22 of RFID sensor antenna 18 and reader 24 is heldOK.As it can be seen, reader 24 can include RFID sensor impedance reader 26 and integratedCircuit memory chip reader 28.Friendship between RFID sensor 12 and pick-up winding 22General mutual inductice coupled circuit model can be used mutually to describe.This model includes pick-up winding 22Intrinsic impedance ZCIntrinsic impedance Z with sensor 12S.Mutual Inductance Coupling M and intrinsic impedance ZC、ZSBy striding across the overall measurement impedance Z of the terminal of pick-up winding 22TIt is correlated with, such as following formula institute tableShow:
ZT=ZC+(ω2M2/ZS) (1)
Wherein, ω is radian carrier frequency, and M is Mutual Inductance Coupling M coefficient.
Via monitoring by the sensing material 14 of the electromagnetism place detection generated in antenna 18 (Fig. 2)The change of character, perform sensing.RFID sensor is being read by pick-up winding 22When 12, the electromagnetic field generated in sensor antenna 18 stretches out from the plane of sensor 12,And by the dielectric properties influence of surrounding, thus provide measure physical parameters, chemistry ginsengNumber and the chance of biological parameter.
Via monitoring by the sensing of the electromagnetism place detection generated in supplementary sensor 23 (Fig. 3)The change of the character of material 14, performs sensing.RFID is being read by pick-up winding 22During sensor 12, the electromagnetic field generated in supplementary sensor 23 is from supplementary sensor 23Plane is stretched out, and by the dielectric properties influence of surrounding, thus measurement physics ginseng is providedNumber, chemical parameters and the chance of biological parameter.
Fig. 4 illustrates the measured sound of the exemplary RFID sensor 12 according to embodiments of the inventionThe example answered, including full impedance spectrum and the spectrum parameter of some independent measurements of sensor.In order to use single RFID sensor, detect some selectively such as RFID sensor 12Steam or fluid, from being coated with the sensor antenna 18 of sensing material to measure impedance spectrumZ (f)=Zre(f)+jZimThe real part Z of (f)re(f) and imaginary part Zim(f), and from measured Zre(f)And ZimF () calculates at least four spectrum parameter, as shown in the curve 30 of Fig. 4.7 can be calculatedIndividual spectrum parameter, as shown in the curve 30 of Fig. 4.These parameters include ZreThe frequency location of (f)FPWith amplitude ZP、ZimResonant frequency F of (f)1With anti-resonance frequency F2, respectively at F1And F2FrequentlyImpedance magnitude Z of rate1And Z2And zero reactance frequency FZ.Also can calculate such as the factor of quality itThe additional parameter of class.From measured parameter, may further determine that the resonant antenna 18 of sensing film coatingResistance R, electric capacity C and other parameter.Multivariate analysis can be used for the dimension of impedance responseFrom the measured real part Z of impedance spectrumre(f) and imaginary part Zim(f) or from calculated parameter FP、ZP、F1And F2And the individual data point that other possible parameter is reduced in hyperspace, it is provided with choosingQuantify different steam or fluid with selecting, this it will be appreciated by persons skilled in the art that, andWill be further described below.
The generally acknowledged restriction bag of the impedance spectra in the real sensor of trace analysis analyte detectionInclude relatively muting sensitivity and big frequency range extremely grown the acquisition time.Embodiment as herein describedBy being put on the electrode of resonant LCR sensor circuit by material, strengthen measurement sensing materialThe ability of change of character.Similarly, the disclosed embodiments strengthen measurement resonance LCR biographyThe ability of the change of the character of the fluid near the electrode of sensor circuit.Experiment test examines and changesBecome the effect with and without the dielectric constant on the sensing electrode of resonator.With conventional impedance lightSpectrum is compared, and naked resonant LCR sensor provides the noise (SNR) that minimum is measured range delta εAt least 100 times of enhancings, wherein there is the corresponding improvement of the detectable limit that dielectric constant determines.
As used the performance of LCR sensor that multivariate analysis tools analyzed to provide individuallyThe selective advantage of improvement of the individually process of response of sensor.Specifically, test resultShow, and compared with the relation between the multivariable parameter presenting larger change, FPWith ZPBetweenIt is right that pass between the sensor resistance R and the sensor capacitance C of calculating of relation and calculating ties up toBetween different steam or fluid, there is small selectivity, discussed in detail below.Additionally,LCR sensor description of test improves the independence of the overall selectivity of the multivariable response of LCR sensorContact resistance and hand capacity response.This selectivity modification is derived from contact resistance and hand capacityRespond the individual contributions that the equivalent circuit to sensor responds.
Multiple group of the RFID sensor of all sensors 12 and 21 as Figure 1-3 etcPart respectively processes multiple physical property, such as but not limited to thermal conductivity, thermal expansion, modulus of elasticity,Resistance, impedance etc..This kind of character can be affected by variations in temperature.Therefore, the temperature of characterRelevant response coefficient is defined as temperature and changes fixed amount, relatively becoming such as character when 1 degree CelsiusChange.Such as, this character can change with linear or multinomial, logarithm or exponential manner with temperature.Properties can increase with temperature, and other character can reduce with temperature.Such as, impedanceTemperature relevant response coefficient at another of sensing material 14 and RFID sensor 12 or 21Assembly is (such as but not limited to memory chip 16, antenna 18, substrate 20, coil 22, collectionBecome circuit (IC) chip, transducer or film) between can be different.In other words, sensing material 14Impedance can be with temperature in the way of being different from other assembly of RFID sensor 12 or 21Change.Such as, for the variations in temperature of 1 degree Celsius, the impedance of sensing material 14 can increase1 ohm.By contrast, for the identical variations in temperature of 1 degree Celsius, RFID sensor 12Or the impedance of the antenna 18 of 21 can increase by 0.8 ohm.Therefore, two temperature of impedance are correlated withPercent difference between response coefficient is about 22%.In various embodiments, LCR circuit andThe absolute value of the temperature relevant response coefficient of the character of sensing material 14 can about 0.5% to500%, between 2% to 100% or 5% to 50%.Based on LCR circuit and the temperature of sensing material 14Degree relevant response coefficient difference, RFID sensor 12 or 21 can with temperature the most independently fromAnalyzed fluid mixture detects analyte fluid selectively.
Fig. 5 is to illustrate to deposit in variable temperature for using RFID sensor 12 or 21 to analyzeFlow process Figure 40 of the demonstration program of steam in case, wherein sensing material 14 and RFIDThe temperature relevant response coefficient of the impedance of other assembly of sensor 12 or 21 differs.UnderIn row step, the multivariate analysis of the impedance of the measurement of RFID sensor 12 or 21 is used for carryingRespond for temperature associated steam.At first step 42, RFID sensor 12 or 21 is via prisonThe change of the character surveying the sensing material 14 by the electromagnetism place detection generated in antenna 18 is heldRow sensing, as described in detail above.At second step 44, the RFID antenna that makes a difference electricityThe temperature fluctuation of the impedance of road and sensing material 14.But, RFID antenna circuit and sensing materialThe impedance of material 14 rings owing to RFID antenna circuit is relevant with the temperature of the impedance of sensing material 14Answer the difference of coefficient rather than by equal impact.It addition, RFID antenna circuit and sensing material 14The difference of temperature relevant response coefficient of impedance affect the impedance spectrum of measurement of resonant antenna.?Three steps 46, RFID sensor 12 or 21 senses the change of the concentration of steam to be quantified.TemperatureDegree fluctuation can continue to occur at third step 46.In the 4th step 48, RFID sensor 12Or 21 measure resonant antenna impedance spectrum.Can count from the real part of the measurement of impedance spectrum and imaginary partCalculate some spectrum parameters, as described in detail above.In the 5th step 50, perform full impedance spectrumOr the multivariate analysis of the spectrum parameter calculated, as described in detail later.
In the 6th step 52, obtain in the memory chip 16 of RFID sensor 12 or 21The suitable multivariate calibration value of storage or calibration factor.Calibration factor in RFID sensor 12 orDetermine during the experiment test of 21.Such as, RFID sensor 12 or 21 is in some temperatureThe vapour concentration that degree sensing changes.Then, PCA or other multivariable technique any orThe combination of person's method can be used for producing each response curve of measured temperature.Determine bestCorresponding to the optimum fit curve of each response curve, and determine such as polynomial function etcFunction, in order to represent optimum fit curve with mathematical way.Each function includes characterizing this letterSome numeric factors of number.Then, these coefficients are used as calibration factor, and they such as can conductLook-up table is stored in memory chip 16.During operation, by RFID sensor 12 orThe concentration of 21 steam sensed and/or temperature be likely not to have corresponding to experimental concentration or temperature itOne.But, the calibration factor using the experiment in look-up table to determine, can generate and be best represented byThe interpolating function (that is, response curve) predicting behavior at the steam of sensed concentration and temperature.
In the 7th step 54, RFID sensor 12 or 21 is based on performed by the 5th step 50Multivariate analysis and unrelated with variable temperature at response curve determined by the 6th step 52Ground quantifies the concentration of steam.Specifically, by the result of many analysis on altered projects of the 5th step 50Substitute at interpolating function determined by the 6th step 52, in order to calculate vapour concentration.CalculateVapour concentration is accurately, because the previous steps in flow process Figure 40 has been contemplated that variable temperatureImpact on RFID sensor 12 or 21.As shown in flow process Figure 40, it is not necessary to independent temperatureSensor, because individually RFID sensor 12 or 21 can be many based on measured resistance valueVariable analysis provides the unrelated steam of temperature to respond.Therefore, RFID sensor 12 can make by ratioWith other sensing system of individual temperature sensors is less, cost is lower, simpler and/orRelatively reliable.
Multiple sensing material is advantageously used on the sensing area of LCR resonant sensor, becauseThe analyte sensing change of sensing material film is by material resistance and electric capacity, transducer and sensing materialThe resistance between contact resistance and electric capacity and transducer substrate and sensing material between material andChange in electric capacity affects the impedance of antenna LCR circuit.This kind of change provides independent RFIDThe multiformity of the response of sensor, and provide the single LCR of employing or RFID sensor to replaceThe chance of the whole array of conventional sensors.
The sensing film of disclosed LCR and RFID sensor can include multiple material, if environmentChange is that the change by resonant LCR circuit parameter is detectable.It addition, the character of sensing filmTemperature relevant response coefficient different from the temperature relevant response coefficient of the character of LCR circuit, asDescribed above in detail.The non-limiting example of possible sensing membrane material is the most poly-(2-firstBase acrylic acid hydroxyl) etc hydrogel, such as Nafion etc sulfonation gatherThe adhesive polymer of compound, such as silicone adhesive etc, such as sol gel film etc inorganicFilm, the containing of such as DNA, antibody, peptide or other biomolecule etc deposited as filmBiomembrane, as inorganic or polymeric membrane, synthesis film, nanometer synthesis film, functionalization(functionalized) carbon nano-tube film or by functionalisation of surfaces golden nanometer particle, Static SpinningPolymerization, inorganic and synthesis nanofiber and there is a dielectric property and being combined in have anotherThe part deposition of the film that the nanoparticle in the matrix of one dielectric property is formed is such asDNA, antibody, enzyme, peptide, polysaccharide, protein, fit or other biomolecule or virus,Spore, cell etc containing biomembrane.
Sensing material can be chosen to the different dielectric with the scope from about 2 to about 40Constant.Non-limiting example include polyisobutylene (PIB, ε 'r=2.1), ethyl cellulose (EC,ε’r=3.4), Polyglycol 166-450 (PECH, ε 'r=7.4), cyanogen hydroxypropyl methyl benzyl silicone(cyanopropyl methyl phenylmethyl silicone) (OV-275, ε 'r=33).Using of these materials provides the adaptation sensing response when being exposed to the steam of differing dielectric constantThe ability of relative direction.Steam enters to the different partition coefficients in these or other sensing materialThe multiformity of one step modulated response and relative direction.
" synthetic " is to keep independent and different in finished product structure on a macro level by havingThe material that constituted of significantly different two or more composition materials physically or chemically.ExampleAs, two or more composition materials can have the different temperatures of the character of such as impedance etc and be correlated withResponse coefficient.The non-limiting example of synthetic includes having poly-(4-Vinyl phenol), poly-(benzeneEthylene propenyl altogether) (poly (styrene-co-allyl alcohol), poly-(vinyl chloride-be total to vinegarVinyl acetate) and the carbon black synthetic of other material." nanocomposite " is by havingProduct structure keeps in nano-scale independent and different significantly different physically or chemically propertyThe material that the two or more composition materials of matter are formed.The non-limiting example of nanocompositeIncluding: there is polymer (the most poly-(N-vinylpyrrolidone), Merlon, polystyreneDeng) carbon nanotube synthetic；There is polymer, metal oxide nano-wire and carbon receiveThe semiconductive nanocrystalline quantum dot nanocomposite of mitron；Use the gold of CNT functionalizationBelong to nanoparticle or nano-cluster (nanocluster).
Sensing material presents analyte response, and this can pass through LCR or the three of RFID sensorThe one or more of individual response mechanism describe, such as resistance variations, change in dielectric constant and swollenSwollen change.Can constitute to combine and respectively by dramatically different response mechanism, analyte be rungThe synthesis sensing material of the independent sensing material of multiple differences answered.This kind of synthesis sensing material producesMultivariable response strengthens multiformity.This kind of synthesis sensing material can specific at LCR resonatorHomogeneity or heterogeneous mixes or be partially formed pattern on part.
Such as, large-scale metal oxide semiconductor material (such as, ZnO, TiO2、SrTiO3、LaFeO3Deng) change of resistance is presented when being exposed to analyte gas, but some mixing goldBelong to oxide (such as CuO-BaTiO3、ZnO-WO3) change it when being exposed to analyte steamDielectric constant/electric capacity.By these materials are combined into mixture or heavy by being spatially separatingAmassing on same sensor, the individual contributions of the local environment around sensor is used for increasing by theyThe multiformity of the response mechanism of strong single analyte, thus strengthen selectivity.
As another example, part coating conduction (such as, metal) nanoparticle is due to themBecause of analyte absorb the local that sensed in part shell expand the strong change of the resistance caused withAnd the follow-up change of the tunneling efficiency between adjacent conductive nanoparticle and these electrical-conductive nanometersThe change in dielectric constant of the environment between particle and be used as steam sensing material.With dielectric polymer(non-limiting example includes silicone, poly-(ether urethane (etherurethane)), polyisobutylene siliconKetone fluorinated alcohols etc.), conjugated polymer (polyaniline, polythiophene, poly-(ethylene ferrocene), poly-(fluorenes-diphenyl propane), poly-(3,4-rthylene dioxythiophene), polypyrrole, two pyrroles(bilypyrrole)) or carry out response analysis thing with the more prominent change of electric capacity or resistance to absorbOther material any (non-limiting example includes porphyrin, metalloporphyrin, metallophthalocyanine, carbonNanotube, semiconductive nanocrystal, metal oxide nano-wire) combine, formation has widerThe sensor of analyte response.
Additionally, in order to avoid disparate materials each other potentially harmful in synthesis sensing materialImpact (such as, the conduction of high dielectric constant suppression conductive filling material), these materials becomeComponent selections origin cause of formation hydrophilic/hydrophobic alternately or each other immiscibility and localized phase separation, thus allowDifferent mechanisms is active in each composition, in order to sensed by sensor.In another embodimentIn, synthesis sensing material can be formed as the individual member deposited on single sensor adjacent one another areThe sector of material.In another embodiment, synthesis sensing material can be formed as overlapping each other heavyAmass the layer of independent material on single sensor.
In certain embodiments, sensing material can be porphyrin, metalloporphyrin, metallophthalocyanine andRelevant macro ring.In these materials, gas sensing is by the layer that organises of gas to flat macro ringPi accumulation or by the gas of metal center be coordinated and do not have cavity to comprise and realize.GoldBelong to porphyrin provide gas response some mechanism, including hydrogen engage, polarization, polarity mutual, goldenGenus center is coordinated mutual and molecules align.Porphyrin, metalloporphyrin, metallophthalocyanine and relevant macro ringMolecule also be able to be assembled in nanostructured.
The material of type includes wherein aliging by multiple known method (dielectrophoresis pair furtherTogether, material polymerization during alignment, because of space limit cause alignment, slow solvent evaporation duringAlignment etc.) perform alignment nanostructured, self-assembled structures (such as, formed objectsThe colloidal crystal structure of particle, wherein different layers have the multilamellar glue of different size of assembling particleBody crystal film, wherein particle have the particle core with a dielectric property and another dielectric propertyParticle shell nucleocapsid structure nanoparticle assemble), bionical (bio inspired) material,Zero dimensional nanometer materials, monodimension nanometer material, two-dimension nano materials and three-dimensional nanometer material.
Self-assembled structures includes that the particle,colloid crystal structure of formed objects, wherein different layers haveThe multilayer colloid crystal film of different size of assembling particle, wherein particle have one dielectricity of bandThe nanoparticle subgroup of the nucleocapsid structure of the particle core of matter and the particle shell of another dielectric propertyDress.The non-limiting example of the material of self-organized colloidal crystal structure includes polystyrene, poly-firstBase acrylic acid methyl ester., polymethylstyrene, styrene/butadiene copolymers, styrene/tolueneEthylene copolymer and Silicon stone.The representative diameter of these colloidal particles depends on the type of material, andAnd scope can be from 50 nanometers to 25 micron.There is colloidal crystal structure non-limiting of multilamellarA kind of size of at least one of which that example includes being assembled in sensor substrate as colloid arrayParticle and be assembled at least one of which another kind size above preceding layer as colloid arrayParticle.The non-limiting example of biomimetic material includes super-hydrophobic or super-hydrophilic coating.
The non-limiting example of zero dimensional nanometer materials includes metal nanoparticle, dielectric nano grainSon, core-shell structure copolymer nanoparticle and semiconductive nanocrystal.The non-limiting of monodimension nanometer material is shownExample includes nanotube, nano wire, nanometer rods and nanofiber.Two-dimension nano materials unrestrictedProperty example includes Graphene.If the non-limiting example of three-dimensional nanometer material includes dried layer colloidal spheresThe self-assembled film of body.
Have the core of the particle shell of particle core with a medium character and another dielectric property-The non-limiting example of the nanoparticle of shell structure includes: metal (gold, silver, their alloyDeng) core nanoparticle and organic shell (dodecyl mercaptans, decanethiol, 1-butyl mercaptan, 2-Ethyl hexyl mercaptan, hexyl mercaptan, tert-dodecyl mercaptan, 4-methoxyl group-toluenethiol, 2-sulfydryl benzeneAnd oxazole, 11-sulfydryl-1-undecyl alcohol, 6-hydroxyl hexyl mercaptan)；Polymerization (polystyrene, poly-Methyl methacrylate) and inorganic shell (Silicon stone)；Isolation core (polystyrene, polymethylacrylic acidMethyl ester, Silicon stone) and semiconductive shell (CNT, TiO2, ZnO, SnO2, WO3) and pointIt is embroidered with the carbon nanotube core of metal nanoparticle.Metal (gold, silver, their alloy etc.) core is receivedThe nanoparticle of rice corpuscles and organic shell can use organic and polymerizable molecular to improve further.The non-limiting example of organic molecule includes porphyrin, metalloporphyrin, metallophthalocyanine and macro ring, caveShape part, super molecular compound.The non-limiting example of polymerizable molecular includes having scope from 2Polymerizable molecular to the differing dielectric constant of 40.Non-limiting example include polyisobutylene (PIB,ε’r=2.1), ethyl cellulose (EC, ε 'r=3.4), Polyglycol 166-450 (PECH, ε 'r=7.4),Cyanogen hydroxypropyl methyl benzyl silicone (OV-225, ε 'r=11), double cyanogen pi-allyl silicone (OV-275,ε’r=33).The non-limiting example manufacturing these sensing materials includes: (1) in a solventPreparation has the metal core nanoparticle having casing, and this is formed and is polymerized by (2) in a solventOr organic molecule another composition mixing, and (3) on LCR or RFID transducer byThis combination mixture makes sensing film.These materials are used in combination with metal core nanoparticleThe energy of the relative direction adapting to sensing response when being exposed to the steam of differing dielectric constant is providedPower.Steam is to the further modulated response of different partition coefficients in these or other sensing materialMultiformity and relative direction.
Other sensing material includes semiconducting metal oxides, zeolite, cryptand, ionic liquidBody, liquid crystal, crown ether, enzyme, polysilsesquioxane, metallic organic framework (MOF).
Other sensing material includes having different polymer pendant groups degree of functionality and different polymer is joinedThe synthesis dielectric of side and conducting polymer；The biomolecule of gas phase sensing；There is leading intracavity joinThe total of steam that the cryptand of position and cryptand deposition are provided suppresses outside nonspecific chamberAbsorb；Porphyrin and as independent molecule and be assembled in polymer and nanostructured relevant pointSon.
In order to improve temperature correction response further, can perform to use the sense of auxiliary membrane filtration filmSurvey the coating of film.The non-limiting example of these filter membranes include zeolite, metallic organic framework andCryptand filter.
The sensing area of LCR or RFID resonant transducer provides and shows as non-limiting exampleThese the multiple sensing materials gone out, because material is passed through in the analyte sensing change of sensing material filmContact resistance between resistance and electric capacity, transducer and sensing material and electric capacity and transducer liningResistance between the end and sensing material and the change of electric capacity affect the impedance of antenna LCR circuit.This kind of change provides the multiformity of the response of independent RFID sensor, and provides employing singleLCR or RFID sensor replace the chance of the whole array of conventional sensors, as described below forExperimental data further illustrates.
Experimental data
All resonant antenna structure as previously discussed etc are used for proving disclosed technology.By oftenRule paint painting, titration coating and spraying process, are applied on resonant antenna by multiple sensing material.The measurement of the impedance of RFID sensor for example with network analhyzer (model is E5062A,Agilent Technologies, Inc., Santa Clara, California), calculatingMachine controls lower use Lab VIEW and performs.Network analhyzer is used for scanning range of interest (i.e.,The resonant frequency range of LCR circuit) frequency, and collect the impedance from RFID sensorResponse.By RFID sensor is put in environmental chamber, and with about 0.1 degree CelsiusAccuracy and precision controlling temperature, produce variations in temperature.
For gas sensing, use the computer of internal build to control steam generating system and produceDifferent vapour concentrations.Collected impedance data use Excel (MicroSoft Inc.,Seattle, the State of Washington) or KaleidaGraph (Synergy Software, inner fourth,Pennsylvania) and with Matlab (The Mathworks Inc., Nei Dike, Ma SaZhu Saizhou) compounding practice PLSToolbox (Eigenvector Research, Inc., gracefulGloomy, the State of Washington).
Example.Single sensor is used the most accurately to detect humidity level
As illustrated in figs. 6-11, test result is obtained, in order to prove to use single sensor (such as,The sensor 12) at some different temperatures, accurately detect water vapour.This kind of test result canFor generating above in relation to the calibration factor described in Fig. 5.As shown in Fig. 6, Fig. 7 and Fig. 9,Sensor is exposed to the water vapor concentration of change under following temperature: 25 degrees Celsius, 30 CelsiusDegree, 35 degrees Celsius and 40 degrees Celsius.Tested water vapor concentration be about 0ppm, 2807ppm,4210ppm, 5614ppm, 7017ppm and 8421ppm.
Carefully select and provide for applying the sensing material of RFID label tag at four temperatureAccurately detect the ability of water vapor concentration.In this experiment, selected sensing material is allSuch as poly-(ether urethane) (PEUT) that the electrodeless solvent of dichloromethane etc dissolves.In experiment periodsBetween, RFID sensor four temperature each under be incrementally exposed to multiple water vapor concentration.Specifically, there is computer control temperature programmed environmental chamber by sensor is positioned atIn, perform measurement.Use the steam generating system with computer control vapour concentration programmingPerform the generation of different water vapor concentration.Test is carried out step by step, wherein, and water vapour denseDegree increases with each step.By monitor the change of some character and check to four temperature withAnd the multiple response of concentration level increased, data prove in above-mentioned experiment temperature independentlyThe ability of accurate quantification water vapor concentration.
Fig. 6 and Fig. 7 illustrates when RFID sensor is for measuring steam (that is, in this exampleWater vapour) time example on the temperature impact of the individually response of RFID sensor.Chart 55 He56 illustrate that the sensor being coated with film is being exposed to about 0,2807,4210,5614,7017With the notable temperature that the electric capacity during water vapor concentration of 8421ppm responds C and electrical response RRelevant.In other words, electric capacity and electrical response change relative to temperature.In fig. 8, relativelyIn be coated with the sensor of film being exposed to about 0,2807,4210,5614,7017 andFor the difference of about 25,30,35 and 40 degrees Celsius during the water vapor concentration of 8421ppmThe electrical response R of temperature draws electric capacity response C.Each lines in Fig. 8 are corresponding in differenceAt a temperature of specific water vapor concentration sensor response.Such as, solid line circle is corresponding to fourAt individual temperature, the sensor to the water vapour of 8421ppm responds.The upper left quarter of lines corresponds toThe response of 40 degrees Celsius, and the right lower quadrant of lines is corresponding to the response of 25 degrees Celsius.Fig. 8 showsGo out the relation between temperature appreciable impact electric capacity and electrical response.Accordingly, it is difficult to come based on Fig. 8Distinguish temperature to affect with water vapor concentration.But as follows, rung by application sensorThe multivariate analysis answered, obtains distinguishing temperature and significantly improving that vapour concentration affects.
A kind of convenient manner of the multiple response of analyte sensors is to use principal component analysis (PCA)Produce multivariate signature.Everybody it will be appreciated that PCA analyze be those skilled in the artThe mathematical procedure analyzed for cube is reduced to more low-dimensional supply known.Such as, givingThe multiple response of each steam determining concentration can be reduced to individual data point, and thus can differentiate canIt is expressed as the single response of each steam of vector, as shown in Figure 9.Fig. 9 represents in aforementioned fourThe PCA curve 60 of the multiple response of six kinds of water vapor concentrations at temperature.Water vapor concentration edgeThe direction of arrow 62 increases.In other words, in the result of the highest water vapor concentration, i.e. 8421ppmOccur near the left side of curve 60, and occur in song in the result of the least concentration of 0ppmNear the right side of line 60, wherein the result at 0ppm overlaps onto individual data to four temperaturePoint.Everybody is it will be appreciated that FACTOR 1 (factor 1) represents the response with maximum change,And FACTOR 2 (factor 2) represents have time response of maximum change.Compared with Fig. 8, Fig. 9The lines of the different vapour concentration of middle expression are more open, thus show to make district by multivariate analysisOther temperature is possible with the improvement of vapour concentration impact.As shown in Figure 9, although water vapour is denseSpend at 25 degrees Celsius of ratios 40 degrees Celsius of larger changes shown relative to FACTOR 1, butIt is can be clearly distinguish between in the result of four temperature.Therefore, according to various embodimentsSensor can correct the impact of these temperature, in order to provides water vapor concentration information accurately.ToolFor body, can be to each formation optimum fit curve of four temperature and respective function.These lettersThe coefficient of number then can be used as calibration factor described above in detail.Correspondingly, this test data carryFor to can be temperature independent differentiate the support of sensor of water vapor concentration.
Use based at the function of the data collected by experimental temperature and calibration factor, can extrapolate orThe impact on the sensor measurement at a temperature of other of the interpolation temperature.For example, it is possible to can extrapolateWater vapor concentration between 25 degrees Celsius and 30 degrees Celsius.This additional extrapolated data can also be used withWater vapor concentration at a temperature of detecting other selectively.Additionally, by selected by changeSensing material, utilizes single RFID sensor to have turned out in temperature in addition to the aboveDegree and concentration detect steam in addition to water selectively.
Other curve can be generated, in order to illustrate further collected by single RFID sensorHow experimental data is for quantifying water vapor concentration temperature independently.Such as, from Fig. 9'sData are for generating the secondary mould formed compared with water vapor concentration shown in left side of Figure 10The multivariable response curve 70 of the FACTOR 1 and FACTOR 2 of type.In other words, two are formedSecondary model is to represent the result of the PCA curve 60 shown in Fig. 9.Described above in detail manyThe predictive value of the water vapor concentration under the conditions of Zhong uses secondary model to calculate, and and Figure 10Curve 72 in actual measured value compare.As shown in the curve 72 of Figure 10, point leans onThe nearly lines corresponding with the slope of.Such as, the standard error of secondary model is about 212ppmWater vapour (that is, 0.7% relative humidity).Therefore, it was predicted that be worth closely related with actual value, fromAnd prove the predictability of exemplary sensor and method.
Similarly, from the data of Fig. 9 for generating shown in the left side of Figure 11 and water vapourThe multivariable response that concentration compares the FACTOR 1 and FACTOR 2 of formed three time model is bentLine 80.In other words, three models are formed to represent the result of the PCA curve 60 shown in Fig. 9.Described above in detail multiple under the conditions of water vapor concentration predictive value use three modelsCalculate, and compare with the actual measured value in the curve 82 of Figure 11.Such as Figure 11Curve 82 shown in, point is near lines corresponding with the slope of.Such as, secondary modelStandard error is about the water vapour (that is, 0.63% relative humidity) of 188ppm.Therefore, asSecondary model with Figure 10 is the same, it was predicted that is worth closely related with actual value, demonstrates again that demonstrationSensor and the predictability of method.In other embodiments, it is possible to use except secondary and threeOther multinomial model outside secondary model.
Although the most only illustrate and describe some feature of the present invention, but those skilled in the artWill recognize that multiple modifications and changes.It is therefore to be understood that claims fall into this anticipated containingAll such modifications and changes within the true spirit of invention.