Array of PZT pyroelectric thick-film sensors for contactless measurement of XY position

This paper presents the design, fabrication, and experimental characterization of a pyroelectric sensor array made by 8×8 pixels of PZT screen printed on alumina substrate. The electrodes are configured as eight columns and eight rows evenly spaced, whose respective crossings form the 64 pixels of the array. When an amplitude-modulated light emitting diode (LED) is placed in front of the array and moved in the XY plane parallel to the array surface, the array and the LED, respectively, work as the reference element and the contactless cursor of a biaxial position sensor. By means of a proper method of readout and processing of the pyroelectric signals, a continuous and linear dependence of the output voltages on XY-position of the LED can be obtained. The system intrinsically rejects background vibrations and microphonics. The configuration can be easily scaled to a larger number of pixels, and migrated to other manufacturing technologies.