UCSD Triton CarPresident: Oliver Molina | Advisor: Professor Pao Chau

Members: Ruiqi Mao, Jason Kim, Jonathan Whitwell, Caleb McGinnis, Charlie Henson, Steve Lopez, Daniel Chilin, Erica Fung, Vincent Li, Raj Khatri, Rose Joo, Sarah Abdulabbas, Quy Hoang, Matt McCoy, Sonya Rhee, Ryien Lu, Alexie Pogue, Adil Mistry, Jason Chow, Santiago Garza

References• Linden,David.HandbookofBatteries.3rded.NewYork:McGraw-Hill, 1995.Print.• “IodineClockReaction.”AmericanChemicalSociety,4March,2012. <http://www.jce.divched.org/jcesoft/cca/cca3/main/clockrx/page1.htm>.

AcknowledgementsWe would like to give special thanks to the following people and organizations for all the help they have provided us throughout the course of our project:

Design ObjectiveTo design and construct a small car that is powered by a chemical energy source.Thecarmusttravelagivendistancecarryingaspecifiedloadandstop.

Safety Practices & Features• Battery:Solid-statedrycellpreventsspillsandminimizeshandlinghazards• Iodine Clock:Theclockcontainerisaspill-proofshock-resistantflask• Secondary Containment: All chemical mixtures are doubly contained • Vehicle Shielding: Thechemicalandmechanicalcomponentsonthecarare shielded by acrylic walls in order to prevent unintended human contact

• Accident Prevention: Every team member was required to complete the university’s“LaboratorySafetyPrinciples”coursebeforeenteringthelab• Proper Waste Disposal: All hazardous waste was disposed of properly• MSDS Binders: Material Safety Data Sheets were made available at all labs

Thevehicle’smotorispoweredbyseveralzinc-carbonbatteriesthathavebeenputinparallelandseriestooutputtheoptimalvoltageandcurrentnecessarytotraversethefull100ftcourseinun-der2minutes,asspecifiedbythecompetitionrules.Thestoppingmechanismconsistsofanio-dine“clock”reactionmonitoredbyaphotoelectricsensor.Whentheclockreactiontakesplace,thesolutioninthecontainerwillturndarkandthephotoelectricsensorwilldetectthiscolorchangeandsubsequentlybreakthecircuit,thus,turningoffthemotorandstoppingthecar.

PropulsionMechanism:Zinc-CarbonBattery• Thebatteryismodeledafteratypicaldrycellbattery,alsoknownasazinc-carbonbattery• Thehalfcellreactionsofsuchbatteryoccurasfollows: Zn(s) → Zn2++(aq) + 2 e−

2MnO2(s) + 2 e− + 2NH4Cl(aq) → Mn2O3(s) + 2NH3(aq) + H2O(aq) + 2 Cl−

• Theactivematerialhasablackpowderyappearanceandconsistsofmanganesedioxidecathodematerial, acetylenecarbonblacktoincreaseconductivityandabsorbmoisture,andammoniumchlorideelectrolyte• Thezincmetalanodeshaveaseparatorpastedinordertopreventsuddencorrosionfromtheelectrolyte• Thecarbonrodsarecurrentcollectors,wheretheelectronscantraveltotheloadandbackintotheanode.• Thebatteryproducesa14Voutputat0.5Aandpowersanelectricmotorthatrunsthecarat1ft/s

• Theclocksolutionisamixtureof0.1MHCl,0.1MNaI,0.01MNa2S2O3,and0.5%starch• ThemixturebeginsasaclearandcolorlessliquidwhichturnsvioletuponadditionofH2O2• Thefollowingtworeactionsoccursimultaneouslywithintheclockmixture: (1)3I-(aq) + H2O2(aq)+2H+(aq) → I3

-(aq)+2H2O(l) (2)I3

-(aq)+2S2O32-(aq) → 3I-(aq) + S4O6

2-(aq)• Whenreaction(2)exhauststheS2O3

2-ions,theI3- ions produced by reaction (1) become

abundantintheclockmixtureandreactwiththestarch,producinganinstantcoloration• Thetimeofcolorationiscontrolledbyvaryingthevolumeof3%H2O2titrated into the mix• ThephotoswitchrecievesaconstantLEDlightinput,andoncethemixtureundergoescolor- ation,thelightisblockedbythemixtureandthephotoswitchautomaticallyshutsoffthecar• Inthisway,thephotoswitchcoupledwiththereactionmixturebecomesachemical“clock” whichstopsthecaratapre-determinedtime,dependingonthevolumeofH2O2added

Trial Data

Iodineclockcalibrationusingthephotoswitchtomeasuret_coloration

• ProfessorPaoChau• ProfessorShirelyMeng• ProfessorJamesKadonaga• SabineFaulhaber• KarenOrcutt• DianaLok

• Jae-WookShin• MaiKhuong• SaschaDuttke• TritonEngineeringStudentCouncil• UCSDNanoEngineeringDeptartment• UCSDAIChE Iodineclockmixtureundergoescolorationandphotoswitchshutsoffthecarinresponse

StoppingMechanism:IodineClock

Testingcarspeedatdifferentvoltageoutputsin order to optimize the speed and battery de-sign.Optimalspeedof1ft/sachievedat14V

Controlled displacement of an electric vehicle using electrochemical cells and a time-calibrated iodine clock reaction coupled with a photoswitch sensor

Testingspeedvs.weightdependance by using sev-eralloadsataconstant14V

Bytitratingdifferentvolumesof3%HydrogenPeroxideintotheclockreactionmixture,onecanmanipulatet_coloration,thatis,thetimeatwhichthemixturedarkensandthecarstops.Thecartravelsataconstant1ft/ssomanipulatingt_colorationsuccesfullymediatestheoveralldisplacementofthecar