Spray coating fabrication: thin film formation on non-planar surface

Abstract

This paper presents a three-dimensional microfabrication and integration technology for MEMS smart materials that utilizes a spray coating method. Spray coating is shown to be most effective for additional deposition on non-planar surfaces. PZT films were formed both on flat and uneven surfaces at a thichess of about lpm. Perovskite structures were formed with suitable heat treatment and ferroelectric P-E hysteresis loop was also obtained. This paper is the first report from our group and other researchers on the deposition of smart materials for MEMS using a spray coating method. Spray coating has been proposed as an effective threedimensional coating method which can be used to deposit piezoelectrics, pyroelectrics, magnetics,'etc. for sensors and actuators. The hydrophilic and hydrophobic . ' ' properties between the substrate surface and ejected liquid are most essential process factors in the spray coating method for improving the film growth conditions.

Spray coating thin polymeric sensor films for Au3+

“…Spray technique is one of the powerful ways to produce a film or coating materials. Resultant characteristics of this technique are highly beneficial to sensor technology, for example, the ability to simultaneously provide high throughput, efficient use of material, increase large surface areas, excellent for distribution of chemosensor and comfortable for use …”

An optimized MEMS-based electrolytic tilt sensor

“…However, the conventional spin-coating method results in a poor uniformity on such surfaces: mostly lack and excess accumulation of PR occurs at the convex and concave corners, respectively. Some alternative methods have been reported to realize a uniform PR coating on non-planar surfaces; spray coating [9,10], electro-deposited PR (EDPR) coating [11]. With the EDPR, a conformal PR patterning is feasible regardless of the geometry and size of the structures, but a conductive film is necessary as plating base layer which makes the process complicated.…”

Design and Fabrication of a Micro Electro Mechanical Systems-Based Electrolytic Tilt Sensor

“…These would result in the disconnection and the short of metal electrodes at convex and concave corners, respectively. 7,8) The technique of the metal electrode formation is limited due to the fact that the conventional spin coating method results in lack or accumulation of photoresist on such surfaces.…”