A　micropump　provides　flow　and　pressure　for　a　lab-on-chip　device,　just　as　a　battery　supplies　current　and　voltage　for　an　electronic　system.　Numerous　micropumps　have　been　developed,　but　none　is　as　versatile　as　a　battery.　One　cannot　easily　insert　a　micropump　into　a　nonterminal　position　of　a　fluidic　line　without　affecting　the　rest　of　the　fluidic　system,　and　one　cannot　simply　connect　several　micropumps　in　series　to　enhance　the　pressure　output,　etc.　In　this　work　we　develop　a　flow　battery　(or　pressure　power　supply)　to　address　this　issue.　A　flow　battery　consists　of　a　+EOP　(in　which　the　liquid　flows　in　the　same　direction　as　the　field　gradient)　and　a　-EOP　(in　which　the　liquid　flows　opposite　to　the　electric　field　gradient),　and　the　outlet　of　the　+EOP　is　directly　connected　to　the　inlet　of　the　-EOP.　An　external　high　voltage　is　applied　to　this　outlet-inlet　joint　via　a　short　gel-filled　capillary　that　allows　ions　but　not　bulk　liquid　flow,　while　the　+EOP＇s　inlet　and　the　-EOP＇s　outlet　(the　flow　battery＇s　inlet　and　outlet)　are　grounded.　This　flow　battery　can　be　deployed　anywhere　in　a　fluidic　network　without　electrically　affecting　the　rest　of　the　system.　Several　flow　batteries　can　be　connected　in　series　to　enhance　the　pressure　output　to　drive　HPLC　separations.　In　a　fluidic　system　powered　by　flow　batteries,　a　hydraulic　equivalent　of　Ohm＇s　law　can　be　applied　to　analyze　system　pressures　and　flow　rates.