**1. Introduction**

Miniaturization of electrical components have inherent advantages like less space usage, low cost, high speed and easy transportation owing to its size and light weight. In most industrial applications of piezoelectric materials, crack-free thick or thin films with a uniform microstructure are required. Lapping down a bulk material to the desired thickness is a tedious and time consuming process and thus corresponding thick films are apparently a promising alternative. Thus better understanding of the fabrication methods is necessary to make future generations of miniaturized components/materials. There are many coating techniques available to develop the materials in nano or micro sizes, which are either expensive or follow a tedious processing deposition methodology. On the other hand, preparation of thick film by the electrophoretic deposition has attained much attention owing to its high versatility, cost effectiveness, simple equipment design and process requirements [1]. Generally, thick films of any solid can be deposited by EPD provided the solid assumes its form as powder or a colloidal suspension [2]. In the following sections

we have included in details the preparation of stable suspensions of KNNT and MgTiO3. EPD comprises of two steps; the first step includes the preparation of a stable suspension of the material to be deposited and movement of the particle towards the oppositely charged electrode and the second step involves the deposition of the particle on the substrate surface to forms a film. After the first two deposition steps, a heat-treatment step is normally needed to further densify the deposited films and to eliminate porosity in the film [3, 4]. Compared to other advanced shaping technique, EPD offers easy control of the thickness and morphology of a deposited film through simple adjustment of the deposition time and applied potential [5].

Considering the environmental and health risks of lead-based materials, leadbased materials in the electronics industry are now being replaced with lead-free material. In lead-free ceramic materials, potassium sodium niobate-based materials have received much attention due to its superior piezoelectric properties and high Curie temperature [6]. A piezoelectric vale of 80pC/N has been reported for pure KNN ceramics prepared by solid state reaction route method [7]. However compared to the pure KNN material, doped materials have got high piezoelectric as well as ferroelectric properties. So far, studies have been carried out to improve the piezoelectric properties of KNN ceramics by partial substitutions of Li at Asite and/or Ta at B-site, [8, 9]. Tantalum doping in the B site has a major effect on the materials properties and a piezoelectric value of 205pC/N has been reported for (K0.5Na0.5)(Nb0.7Ta0.3)O3 (KNNT) ceramics [10]. Even though the bulk ceramics such as KNNT and MgTiO3 based materials have good electronic properties [10], miniaturizations of electronic devices demand smaller and lighter components with properties comparable to that of bulk material. Potassium Sodium Niobate (KNN) based layers are being employed in applications such as high frequency transducer and in ultra sound imaging [11, 12] and magnesium titanate (MgTiO3) based materials are used in many applications such as high density capacitors, resonators and filters, in wireless communication systems, global positioning system, antennas for communications, radar and broadcasting satellite, operating at micro-wave and millimeter-wave frequencies [13]. The versatile use MgTiO3 is due to its high quality factor (Qf = 160,000 GHz, Qf = 1/tanδ), low dielectric constant (εr ~ 17) and negative temperature coefficient of resonant frequency (τf = − 50 ppm/°C) [14].
