Thefutureofmedicineisvast--andit'salsoamazinglysmall.Onedayinthenextcentury,thankstotheburgeoningfieldofnanotechnology,youcouldwalkoutofthedoctor'sofficewithaprescriptionforcancerdetectorssotinyyoucan'tseethem.InthisLilliputianworld,unitsaremeasuredinnanometers--10,000timessmallerthanthediameterofasinglehumanhair.Theideaisthatifwecanbuildnewdrugsanddevicesmoleculebymolecule,thewaythetissuesandorgansinourownbodiesareformed,wecanmakethemmuchmoretargetedandeffective.Oneofthehottestareasofnanoresearchisbetterdrugdelivery.Scientistsarenowworkingonaminiaturizedsensorfordiabeticsthatmimicstheglucose-detectionsysteminahealthybody.Thedevice,possiblyimplantedundertheskin,wouldmonitorblood-sugarlevels,thenreleaseinsulinasneeded.AndresearchersatMITrecentlemadeaprototypeforanentiremimi-pharmacy:amicrochip(implantedorswallowed)withasmanyas1,000tinyreservoirs-eachthesizeofapinprick-thatcanhold25nanolitersofanythingfrompainkillerstoantibiotics.MIT'sRobertLngersaysthechip,nowthesizeofadime,canbemadeevensmaller.Andheplanstomakeit"smart"byaddingasensorthatwillknowwhentoreleaseadrugandwhatthedoesshouldbe.