ability ▁after ▁U V R ▁expos ure ▁can ▁lead ▁to ▁an ▁increase ▁in ▁the ▁number ▁of ▁particles ▁that ▁per me ate ▁the ▁skin , ▁the ▁specific ▁per me ability ▁of ▁skin ▁after ▁U V R ▁expos ure ▁relative ▁to ▁particles ▁of ▁different ▁sizes ▁and ▁materials ▁has ▁not ▁been ▁determined . ▁ ▁There ▁are ▁other ▁methods ▁to ▁increase ▁nan op article ▁pen etr ation ▁by ▁skin ▁damage : ▁t ape ▁stri pping ▁is ▁the ▁process ▁in ▁which ▁t ape ▁is ▁applied ▁to ▁skin ▁then ▁lifted ▁to ▁remove ▁the ▁top ▁layer ▁of ▁skin ; ▁skin ▁ab ras ion ▁is ▁done ▁by ▁sh aving ▁the ▁top ▁ 5 - 1 0 ▁mic rom eters ▁off ▁the ▁surface ▁of ▁the ▁skin ; ▁chemical ▁enh ancement ▁applies ▁chemical s ▁such ▁as ▁poly vin yl py r rol id one ▁( P VP ), ▁dim eth yl ▁sul fox ide ▁( D MS O ), ▁and ▁o le ic ▁acid ▁to ▁the ▁surface ▁of ▁the ▁skin ▁to ▁increase ▁per me ability ; ▁elect rop oration ▁increases ▁skin ▁per me ability ▁by ▁the ▁application ▁of ▁short ▁p uls es ▁of ▁electric ▁fields . ▁The ▁p uls es ▁are ▁high ▁voltage ▁and ▁on ▁the ▁order ▁of ▁mill iseconds ▁when ▁applied . ▁Ch arg ed ▁mole cules ▁pen et rate ▁the ▁skin ▁more ▁frequently ▁than ▁neutral ▁mole cules ▁after ▁the ▁skin ▁has ▁been ▁exposed ▁to ▁electric ▁field ▁p uls es . ▁Results ▁have ▁shown ▁mole cules ▁on ▁the ▁order ▁of ▁ 1 0 0 ▁mic rom eters ▁to ▁easily ▁per me ate