CONTROLLED PATTERN PIEZOELECTRIC COMPOSITES
Original Publication Date: 1984-Dec-31
Included in the Prior Art Database: 2004-Apr-04
Xerox Disclosure Journal
Piezoelectric composites, such as those useful for ink jet drop generators, can be fabricated utilizing ceramic particles which can have strong piezoelectric proper-ties (e.g., PZT) and a polymer which provides desirable mechanical properties. Such composites have the added advantage of being capable of manufacture in much larger areas than typical solid ceramic materials.
, XEROX DISCLOSURE JOURNAL
CONTROLLED PATTERN PIEZOELECTRIC Proposed Classification COMPOSITES U.S. CI. 346/75
Doyle P. Skinner Int. CI. Gold 15/18
Piezoelectric composites, such as those useful for ink jet drop generators, can be fabricated utilizing ceramic particles which can have strong piezoelectric proper- ties (e.g., PZT) and a polymer which provides desirable mechanical properties. Such composites have the added advantage of being capable of manufacture in much larger areas than typical solid ceramic materials.
A major difficulty in the fabrication of piezoelectric composite materials lies in achieving a satisfactory dispersal of the active (ceramic) areas in the composite sheet. In order to make best use of the ceramic's properties, the ceramic particles should be connected electrically and mechanically from one electroded polymer film surface to the other. This parallel connection nature allows the application of large electric fields to the high permittivity ceramic which are necessary to electrically polarize it and, hence, make it piezoelectrically active. The stiff mechanical connection nature in this same direction is also desirable as it allows more efficient transmission of mechanical forces. If the ceramic areas are not contiguous laterally but rather isolated from each other by a compliant polymer matrix, the transmission of mechanical forces in the plane of the film will be impeded. This is a desirable alteration in properties over a "single phase" piezo- electric or a composite in which the stiff ceramic phase has lateral continuity.
In order to controllably locate the active ceramic areas in the film, the matrix polymer should be formed or altered to contain desirable size(s) holes arranged in a predetermined pattern. The holes will then be filled with the ceramic by a suitable means. Methods to make the hole patterns include drilling, pinching, and the forming of the polymer in a suitable mold. Laser drilling is a particularly applicable means for creating such hole patterns in suitable matrix polymers, such as polyethylene or polyurethane.
Various means may be employed f...