Patterning of dielectric nanoparticles using dielectrophoretic forces generated by ferroelectric polydomain films

Abstract

A theoretical study of a dielectrophoretic force, i.e., the force acting on an electrically neutral particle in the inhomogeneous electric field, which is produced by a ferroelectric domain pattern, is presented. It has been shown by several researchers that artificially prepared domain patterns with given geometry in ferroelectric single crystals represent an easy and flexible method for patterning dielectric nanoobjects using dielectrophoretic forces. The source of the dielectrophoretic force is a strong and highly inhomogeneous (stray) electric field, which exists in the vicinity of the ferroelectric domain walls at the surface of the ferroelectric film. We analyzed dielectrophoretic forces in the model of a ferroelectric film of a given thickness with a lamellar 180° domain pattern. The analytical formula for the spatial distribution of the stray field in the ionic liquid above the top surface of the film is calculated including the effect of free charge screening. The spatial distribution of the dielectrophoretic force produced by the domain pattern is presented. The numerical simulations indicate that the intersection of the ferroelectric domain wall and the surface of the ferroelectric film represents a trap for dielectric nanoparticles in the case of so called positive dielectrophoresis. The effects of electrical neutrality of dielectric nanoparticles, free charge screening due to the ionic nature of the liquid, domain pattern geometry, and the Brownian motion on the mechanism of nanoparticle deposition and the stability of the deposited pattern are discussed.

Pyroelectric Trapping and Arrangement of Nanoparticles in Lithium Niobate Opposite Domain Structures

“…On the other hand, neutral particles will be polarized due to the electric field of the sample charge, and therefore will suffer an attractive force of dielectrophoretic character exclusively. Clearly this force is weaker than that acting on the charged particles 15 . In addition, in the hypothetical event of equal density of charged and uncharged particles, and assuming that both types of particles have equal sizes and average speeds, relatively greater proportion of charged particles will be trapped.…”

“…They provide a very interesting way for controlled trapping and manipulation of NPs. In principle, the corresponding electro-kinetic forces can act either on charged particles (electrophoresis) or on neutral particles (dielectrophoresis) as extensively discussed in the theoretical work reported by P. Mokry et al 15 . However, previous reported experiments that use pyroelectric generated space-charge distributions on the surface of PPLN structures refer only to dielectrophoresis 7,8,16 .…”

LiNbO3: A photovoltaic substrate for massive parallel manipulation and patterning of nano-objects

“…One approach takes advantage of the electric field distribution generated under UV illumination at the surface of a patterned undoped LiNbO 3 , consisting of domains having alternative poling vectors and so alternative surface charges. The corresponding field distribution, showing high peak values at the domain boundaries, have been calculated 17 and can be used for patterning of nanoparticles through two different strategies. One uses the DEP and EP forces generated by those field patterns as in the PV tweezers to decorate the domain boundaries.…”

“…[11][12][13][14] This strategy can be easily integrated in lab-on-chip devices. 15 Following this strategy, domain structuring of ferroelectric surfaces [16][17][18] allows the use of the associated electrostatic fields and/or suitable electrochemical reactions for manipulation and patterning of molecules and nanoparticles. [19][20][21] Pyroelectric fields in domain structured ferroelectric surfaces have been also proposed to induce the dielectrophoretic (DEP) forces required for nanoparticle patterning.…”

Optoelectronic tweezers under arbitrary illumination patterns: theoretical simulations and comparison to experiment

“…Conversely, the theoretical description of the physics involved is at the beginning. One early paper [13] described particle trapping by DEP forces but appear in a different context (induced by electric fields appearing in ferroelectric domain structure). More recently, a theoretical approach already addressed to optoelectronic tweezers has been developed in two contributions [14,15], although it is essentially focused to periodic light illumination.…”