Assembly of PZT Fibre Array Composites by Dielectrophoresis

An experimental technique for manipulation and assembly of composite materials and structures is described which uses dielectrophoretic forces to pick and place individual components on the micro-scale. This is an inherently low-temperature process which can be viewed as an enabling technique to assemble a large variety of hybrid structures and MEMS devices incorporating different materials and geometries. The new assembly process is a variation of the recently reported electric-field structuring or dielectrophoretic assembly technique. A voltage is applied between movable upper needle-like electrodes and a fixed bottom flat electrode, which are both immersed in a dielectric fluid. PZT fibres are exposed to the electric field and, under suitable conditions of field topology and frequency, they become polarised and they then exhibit a mutually attractive force. By moving the upper electrode through the calibrated holes of an array template, it is possible to drag individual fibres into a pre-determined spatial configuration. Once in situ the fibres can be fixed in place to form a composite array.