A reconfigurable and portable acoustofluidic system based on flexible printed circuit board for the manipulation of microspheres

Xin Yang,Aled Clayton,Yongqing Fu,Hanlin Wang,Xiaoyan Zhang,Chao Sun,Mercedes Stringer Martin,Lin Ye,Zhiqiang Dong,Roman Mikhaylov,Victory Akhimien,Fangda Wu,Povilas Dumcius,Zhenlin Wu

doi:10.1088/1361-6439/ac0515

Abstract

Acoustofluidic devices based on surface acoustic waves (SAWs) have been widely applied in biomedical research for the manipulation and separation of cells. In this work, we develop an accessible manufacturing process to fabricate an acoustofluidic device consisting of a SAW interdigital transducer (IDT) and a polydimethylsiloxane microchannel. The IDT is manufactured using a flexible printed circuit board pre-patterned with interdigital electrodes that is mechanically coupled with a piezoelectric substrate. A new microchannel moulding technique is realised by 3D printing on glass slides and is demonstrated by constructing the microchannel for the acoustofluidic device. The flexible clamping mechanism, used to construct the device, allows the reconfigurable binding between the IDT and the microchannel. This unique construction makes the acoustofluidic device capable of adjusting the angle between the microchannel and the SAW propagation, without refabrication, via either rotating the IDT or the microchannel. The angle adjustment is demonstrated by setting the polystyrene microsphere aggregation angle to −5°, 0°, 6°, and 15°. Acoustic energy density measurements demonstrate the velocity of microsphere aggregation in the device can be accurately controlled by the input power. The manufacturing process has the advantages of reconfigurability and rapid-prototyping to facilitate preparing acoustofluidic devices for wider applications.

Highlights

Acoustofluidic devices have attracted great interest in label-free manipulations of micro-1 and nano- particles[2] owning to their considerable biocompatibility and precision
Compared to cleanroom made Standing SAW (SSAW) devices, the Versatile Acoustofluidic Device (VAD) depended on the manual alignment of the two interdigital transducers (IDTs) to produce an accurate SSAW and form an even distribution of pressure node (PN) and pressure antinode lines
When the two IDTs are in parallel (Fig. 5B), which is within an acceptable working range of conventional Surface acoustic wave (SAW) devices[25]

Summary

Introduction

Acoustofluidic devices have attracted great interest in label-free manipulations of micro-1 and nano- particles[2] owning to their considerable biocompatibility and precision. Surface acoustic wave (SAW) devices are almost independent from the microchannel material in terms of acoustic properties compared to bulk acoustic wave devices[12]. This feature makes them easy to fabricate for high-frequency applications (MHz-GHz)[3,13] and integrate with other systems, such as microfluidics. Standing SAW (SSAW) devices, constructed by a pair of opposite IDTs working on the same frequency, are primarily used in acoustofluidic applications[16]

Methods

Results

Conclusion