text-8-how-nanotechnology-worksVIP专享VIP免费

There'sanunprecedentedmultidisciplinaryconvergenceofscientistsdedicatedtothestudyofaworldsosmall,wecan'tseeit--evenwithalightmicroscope.Thatworldisthefieldofnanotechnology,therealmofatomsandnanostructures.Nanotechnologyissonew,nooneisreallysurewhatwillcomeofit.Evenso,predictionsrangefromtheabilitytoreproducethingslikediamondsandfoodtotheworldbeingdevouredbyself-replicatingnanorobots.Inordertounderstandtheunusualworldofnanotechnology,weneedtogetanideaoftheunitsofmeasureinvolved.Acentimeterisone-hundredthofameter,amillimeterisone-thousandthofameter,andamicrometerisone-millionthofameter,butallofthesearestillhugecomparedtothenanoscale.Ananometer(nm)isone-billionthofameter,smallerthanthewavelengthofvisiblelightandahundred-thousandththewidthofahumanhair[source:BerkeleyLab].Assmallasananometeris,it'sstilllargecomparedtotheatomicscale.Anatomhasadiameterofabout0.1nm.Anatom'snucleusismuchsmaller--about0.00001nm.Atomsarethebuildingblocksforallmatterinouruniverse.Youandeverythingaroundyouaremadeofatoms.Naturehasperfectedthescienceofmanufacturingmattermolecularly.Forinstance,ourbodiesareassembledinaspecificmannerfrommillionsoflivingcells.Cellsarenature'snanomachines.Attheatomicscale,elementsareattheirmostbasiclevel.Onthenanoscale,wecanpotentiallyputtheseatomstogethertomakealmostanything.Inalecturecalled"SmallWonders:TheWorldofNanoscience,"NobelPrizewinnerDr.HorstSt?rmersaidthatthenanoscaleismoreinterestingthantheatomicscalebecausethenanoscaleisthefirstpointwherewecanassemblesomething--it'snotuntilwestartputtingatomstogetherthatwecanmakeanythinguseful.Nanotechnologyisrapidlybecominganinterdisciplinaryfield.Biologists,chemists,physicistsandengineersareallinvolvedinthestudyofsubstancesatthenanoscale.Dr.St?rmerhopesthatthedifferentdisciplinesdevelopacommonlanguageandcommunicatewithoneanother[source:St?rmer].Onlythen,hesays,canweeffectivelyteachnanosciencesinceyoucan'tunderstandtheworldofnanotechnologywithoutasolidbackgroundinmultiplesciences.Oneoftheexcitingandchallengingaspectsofthenanoscaleistherolethatquantummechanicsplaysinit.Therulesofquantummechanicsareverydifferentfromclassicalphysics,whichmeansthatthebehaviorofsubstancesatthenanoscalecansometimescontradictcommonsensebybehavingerratically.Youcan'twalkuptoawallandimmediatelyteleporttotheothersideofit,butatthenanoscaleanelectroncan--it'scalledelectrontunneling.Substancesthatareinsulators,meaningtheycan'tcarryanelectriccharge,inbulkformmightbecomesemiconductorswhenreducedtothenanoscale.Meltingpointscanchangeduetoanincreaseinsurfacearea.Muchofnanosciencerequiresthatyouforgetwhatyouknowandstartlearningalloveragain.Sowhatdoesthisallmean?Rightnow,itmeansthatscientistsareexperimentingwithsubstancesatthenanoscaletolearnabouttheirpropertiesandhowwemightbeabletotakeadvantageoftheminvariousapplications.Engineersaretryingtousenano-sizewirestocreatesmaller,morepowerfulmicroprocessors.Doctorsaresearchingforwaystousenanoparticlesinmedicalapplications.Still,we'vegotalongwaytogobeforenanotechnologydominatesthetechnologyandmedicalmarkets.Intheworldof"StarTrek,"machinescalledreplicatorscanproducepracticallyanyphysicalobject,fromweaponstoasteamingcupofEarlGreytea.Longconsideredtobeexclusivelytheproductofsciencefiction,todaysomepeoplebelievereplicatorsareaveryrealpossibility.Theycallitmolecularmanufacturing,andifiteverdoesbecomeareality,itcoulddrastic...