The pick and place ability, precise positioning and high spatial resolution of end-effector can be defined as the functional requirements of dielectrophoretic tweezers. The tweezers can manipulate objects in any direction with the strength of dielectrophoretic force. A localized and 3D movable electric field configuration is proposed here and analyzed for the functional requirements of dielectrophoretic tweezers. To achieve a steeply focused field, an electrochemical machining method was developed for a sharp probe electrode, and the developed dielectrophoretic tweezers was used to manipulate cells and beads. (C) 2006 Elsevier B.V. All rights reserved.