Screen-printed ultrasonic 2-D matrix array transducers for microparticle manipulation

Abstract

This paper reports the development of a two-dimensional thick film lead zirconate titanate (PZT) ultrasonic transducer array, operating at frequency approximately 7.5MHz, to demonstrate the potential of this fabrication technique for microparticle manipulation. All layers of the array are screen-printed then sintered on an alumina substrate without any subsequent patterning processes. The thickness of the thick film PZT is 139±2μm, the element pitch of the array is 2.3mm, and the dimension of each individual PZT element is 2×2mm(2) with top electrode 1.7×1.7mm(2). The measured relative dielectric constant of the PZT is 2250±100 and the dielectric loss is 0.09±0.005 at 10kHz. Finite element analysis was used to predict the behaviour of the array and to optimise its configuration. Electrical impedance spectroscopy and laser vibrometry were used to characterise the array experimentally. The measured surface motion of a single element is on the order of tens of nanometres with a 10Vpeak continuous sinusoidal excitation. Particle manipulation experiments have been demonstrated with the array by manipulating Ø10μm polystyrene microspheres in degassed water. The simplified array fabrication process and the bulk production capability of screen-printing suggest potential for the commercialisation of multilayer planar resonant devices for ultrasonic particle manipulation.

Advances in Micromanipulation Actuated by Vibration-Induced Acoustic Waves and Streaming Flow

“…One of the important characteristics of micromanipulation based on BAWs is using high-frequency vibration to induce ultrasonic waves. Thus, to emphasize the high frequency used, the micromanipulation based on BAWs can be divided to manipulation by ultrasonic traveling waves (UTWs) and ultrasonic standing waves (USWs) [26,27]. [16], which is a widely used scheme; (b) dynamic acoustic field micromanipulation device based on standing surface acoustic wave (SSAW).…”

“…With the orderly switching of the transducer array below, particles can move freely in the direction of the array arrangement, which is similar to the principle of a magnetic levitation train. Based on the same principle, Qiu et al [27] expanded the array to a two-dimensional scale, constructing an operation method to control the movement of particles in 3D space. Related research is much older, such as the research of Kozuka et al [15], but it is not particularly popular.…”

2-D crossed-electrode transducer arrays for ultrasonic particle manipulation

“…The crossed-electrode array described here was fabricated from thick film PZT (IKTS-PZ5100 [5], Fraunhofer IKTS, Germany) using a screen-printing process reported elsewhere [4]. A 140-µm-thick 15 mm × 15 mm piezoelectric layer was printed and sintered on a 250-µm-thick 100 mm × 100 mm alumina substrate (99.6%, Rubalit 710, CeramTec AG, Germany).…”

“…The functionality of the crossed-electrode array for particle manipulation was tested with planar resonators [1], [4]. A 6 mm wide, 300 µm thickness glass capillary (VitroCom, Mountain Lakes, NJ, USA) was used as a fluid chamber to levitate and concentrate microparticles.…”

“…Reliable driving and control electronics are also required for specific applications. The authors have previously demonstrated that 2-D matrix arrays made with thick film PZT have significant advantages in simplifying the fabrication process and allowing for integration of miniature electronics [4]. This paper explores the feasibility of developing thick film 2-D arrays with the crossed-electrode configuration, also called row-column addressing.…”