A paper by Todd Martin Sames on the emerging technology of light-based identification for small applications on handheld devices.

1. By Todd Martin Sames
to perform identification, authentication and
detection from your cell phone?
WHY NOT use the power of LIGHT

2. IMAGINEif youwere livinginathirdworldcountry and were concernedaboutthe safetyof the
water.Throughthe use of a small,low-cost,portabledevice you couldhave the abilityto instantly
determine if the waterwascontaminatedandunsafe todrink.
Or, let’ssay youare inlaw enforcementandwantto determineif thatwhite powderisbaking sodaor
methamphetamine. Throughthe use of a lightscannerinyour car (possiblyincorporatedintoyour
phone or tablet) you,asthe officer,could quicklyandaccuratelydetermine if itwasinnocentbaby
powderor insidiousmethamphetamine.Todayatest labwouldbe needed tomake thatdetermination.
Or, as a hospital administrator, youmaybe concernedaboutcounterfeitpharmaceutical drugsbeing
suppliedtopatients. Infact,there isa light-basedremedyforthis aswell. If the hospital couldeasily
and inexpensivelyuse lighttomonitorthe purityof drugs,the problemandthe liabilityassociatedwith
it couldbe eliminated.
HOW?
All these of these examples andhundredsmore are veryreal issuesinourworldtoday. Utilizinglightto
determine whatsomethingis andis not hasbeenhappening since the 1940’s. The scientificcommunity
referstothese methodsof light-basedidentification as“spectrophotometry,”andthe devicesusedto
performthese testsas “spectrophotometers.”
Here is howitworks (see image below.) A high-quality white lightsource isprojectedontoasample,in
thiscase, a redleaf.A fiberopticwandcapturesthe reflectedredlightfrom the leaf andfocusesitinto
the spectrophotometer. Insidethe spectrophotometer,the lightistransmittedontoamirror.The
mirrorfocusesthe lightontoa prismwhere the single streamof lightissplitintothe primaryvisible
spectrumcolors. The lightisthentransmittedontoanothermirrorwhichinturn shinesthe lightintoa
device calledadiffractiongrating.The diffractiongratingsendsthe lightasan analog waveformintoa
computerwhere the dominantlightfrequency(red) isthenpresentedinagraphicformat.
The resultingcurve andthe pointsthat compose itdefine aunique lightsignatureforthatspecifictype
of redleaf. (Once a libraryof knownsubstanceshasbeenrecorded, itisfairlystraightforwardtouse a
spectrophotometertodetermine whatthe itemisbymatchingthe unknownitemtothe knownlibrary
of graphs.)

3. Spectrophotometer Computer White light source
Some of the companieswhomake spectrophotometers today are Agilent,Ocean Optics,and
PerkinElmertoname justa few. Thisisa multi-billion-dollarmarketworldwide. Generally,these are lab-
baseddevices –not portable -- thatare large and/orexpensive andrequire atrainedprofessional touse
themand to interpretthe datatheydeliver.
But whatif youhad smallerapplicationneeds? Dr. Tom Furnessatthe Universityof Washingtonand
hisindependentRAT(rockingandthinking) Lab,have developedthisexacttechnology.
TheirChromaIDscanneris builtusing low-cost,off-the-shelf partssuchas LEDs (lightemittingdiodes)
and photodiodes. These componentsare readilyavailable andare foundincameras,tablets,sensors
and othermainstreamproducts.
Here is how Dr. Furness’stechnology works(again,see imagebelow.)
The scanner pulseslightfromthe LEDsonto the redleaf. The lightfromthe specificfrequencyLEDsis
reflectedandcapturedbyphotodiodes(like inyourphone ordigital camera.) Thatanalogstreamof
photonsisconvertedintoadigital dataset of lettersandnumbers. Each pulse of lightgenerates a
digital datasetand each scan pulsesthe LEDshundredsorthousandsof times. The resultisa
light(photon)-baseddigital signaturerepresentingthe redleaf. Muchlike the spectrophotometer,a
libraryof knownscans isrecordedandthe unknownsubstance ismatchedagainstthe knownlight
signature fora match (or not.)
Thissignature isgeneratedbypulsingLEDsat specificfrequenciesof lightandrecordingthe photon
streamusingthe photodiodes.These wavesof photonsare thendigitizedresultinginhundredsor
thousandsof unique datapointsthatcharacterize eachunique item.

4. ChromaID 12 LED scan head
What Dr. Furnessandhisteam discoveredisthatalmosteverythinginnature hasa unique optical
signature if youlookinboththe visibleand invisibleareas of the lightspectrum. Forexample,ageneric
aspirinhasa differentphotonicsignature, referredtoasa ChromaIDsignature,fromthatof a name-
brand aspirin.
Ratherthan lookat approximately400 different frequenciesof humanlyvisible light asthe old
technologydoes,the ChromaIDtechnologyuseslessthan30 specificfrequenciesof light -- some inthe
visible spectrumandsome inthe invisible areasof low ultravioletandhighinfraredlight. Eachscan
headcontainsLEDs that emitspecificfrequenciesof light. Whenthe lightisreflectedoff of asubstance,
the resultingphotonstreamiscapturedbya photodiode,muchlike the way apicture on yourphone is
captured. The photonstreaminformationistransformedintoadigital datasetthat representsthat
particularsubstance’sChromaIDsignature.
Once the “known”original itemhasitssignature recordedinthe database withitsownunique
ChromaIDsignature,itcan be matchedagainstall similarsubstancestoverifythe accuracyor
authenticityof thatsubstance.
The applicationsforthistechnologycanbe almostlimitlesswhetheritisusedforidentifying foodfor
accuracy or contamination, identifyingcounterfeitsecuritycardsorcurrency,or evendetectingaskin
conditionthatmaybe serious.
The matchingprocessusesvariousalgorithmstocompare the data immediately,whichprovides real-
time results(insteadof waitinghoursordaysfor labresults.) One canimmediatelyknow whetheror
not the itemscannedisa legitimate itemora counterfeititem. Inaddition,there isnoneedfora lab
technician toexplainthe results since the dataispresentedinaneasy-to-interpretformatonthe device
beingusedsuchas a tabletor cell phone.

5. COST?
Traditional spectrophotometerscostthousandsof dollars. The costof thisscanningdevice can
potentiallybe lessthan $5. Evennow,thistechnologycouldbe addedtodevicesinanynumberof
vertical industryapplicationsfrommedical analysis,foodsafety,pharmaceuticals,waterquality,process
control,and security.There are evenpatentsappliedforusingthe technologyfordiamondand
gemstone grading.
WHEN?
The last centurywasthat of the electron. In thisnew centurythe use of the photon,andin particular
lightphotons,will become the technologyof choice goingforward. Aswithmanyemerging
technologies,marketacceptance andinvestmentwilldetermine the trajectoryof thisgame-changing
ChromalIDtechnology.
__________________________________________________________________________________
Thistechnologyforauthenticationandidentificationrequirementsinasmall formfactoris available
throughVisualant,Inc.of Seattle,WA.
ChromalIDisa trademarkedtermforDr. Furness’technology.
All graphicscomplimentsof Visualant,Inc.
Todd Martin Samesisan emergingtechnologyindustryveteranwithapointedinterestinthe future of
identification,authentication,assetmanagement,securityanddigital entertainment. Althoughhis
expertiseisinSalesandManagement,he’sabitof a techjunkie. Hence,he justthoughtyoumightwant
to knowaboutthis,too.