DIELECTROPHORETIC　(DEP)　manipulation　has　recently　gained　much　attention　from　nanotechnologists　and　has　been　applied　for　various　nanoentity　assembly　and　manipulation,　such　as　forming　chains　of　nanoparticles　and　nanowires　as　sensing　elements.　For　example,　when　a　gold　colloid　suspension　is　subjected　to　an　ac　electric　field,　＇gold　pearl　chains＇　will　form　due　to　DEP　force.　In　this　article,　the　frequency-dependent　DEP　manipulation　of　gold　nanoparticles　is　analyzed　using　the　coreshell　sphere　model.　The　simulated　relation　between　electric　field　frequency　and　DEP　response　is　found　to　agree　well　with　the　experimental　results,　where　the　rate　of　gold　pearl　chain　formation　tended　to　zero　at　high-　and　low-frequency　limits　and　had　a　maximum　within　a　narrow　midrange　frequency　band.　The　appropriate　control　conditions　for　2-nm　gold　particle　assembly　using　DEP　are　also　estimated　through　the　comparisons　among　DEP,　Brownian　motion,　gravity,　and　fluid　flows　induced　by　electric　field.　On　the　other　hand,　if　an　optical　beam　is　used　to　generate　the　nonuniform　electric　field　and,　consequently,　the　DEP　force　(i.e.,　＇Optical　DEP＇　or　ODEP),　to　manipulate　nanoparticles　in　static　fluidic　medium,　then　drag　force　and　Brownian　motion　must　be　considered　in　understanding　the　movement　of　particles.　©　2010　IEEE.