학술논문

Acousto-Pi: An Opto-Acoustofluidic System Using Surface Acoustic Waves Controlled With Open-Source Electronics for Integrated In-Field Diagnostics
Document Type
Periodical
Source
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control IEEE Trans. Ultrason., Ferroelect., Freq. Contr. Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on. 69(1):411-422 Jan, 2022
Subject
Fields, Waves and Electromagnetics
Fluorescence
Cameras
Hardware
Costs
Surface acoustic waves
Surface acoustic wave devices
Optical filters
Feedback control
fluorescence imagining
integrated acoustofluidics
open-source electronics
piezoelectric thin film
point-of-care (POC) diagnostics
surface acoustic waves (SAWs)
Language
ISSN
0885-3010
1525-8955
Abstract
Surface acoustic wave (SAW) devices are increasingly applied in life sciences, biology, and point-of-care applications due to their combined acoustofluidic sensing and actuating properties. Despite the advances in this field, there remain significant gaps in interfacing hardware and control strategies to facilitate system integration with high performance and low cost. In this work, we present a versatile and digitally controlled acoustofluidic platform by demonstrating key functions for biological assays such as droplet transportation and mixing using a closed-loop feedback control with image recognition. Moreover, we integrate optical detection by demonstrating in situ fluorescence sensing capabilities with a standard camera and digital filters, bypassing the need for expensive and complex optical setups. The Acousto-Pi setup is based on open-source Raspberry Pi hardware and 3-D printed housing, and the SAW devices are fabricated with piezoelectric thin films on a metallic substrate. The platform enables the control of droplet position and speed for sample processing (mixing and dilution of samples), as well as the control of temperature based on acousto-heating, offering embedded processing capability. It can be operated remotely while recording the measurements in cloud databases toward integrated in-field diagnostic applications such as disease outbreak control, mass healthcare screening, and food safety.