Microfluidic Mixer with Automated Electrode Switching for Sensing Applications

Author(s)

Braunger, Maria L. ^[1] ; Fier, Igor ^[2] ; Rodrigues, Varlei ^[1] ; Arratia, Paulo E. ^[3] ; Riul, Jr., Antonio

Affiliation

^[1] Univ Campinas UNICAMP, Gleb Wataghin Inst Phys, Dept Appl Phys, Campinas 13083859, SP - Brazil

^[2] Quantum Design Latin Amer, Campinas 13080655, SP - Brazil

^[3] Univ Penn, Dept Mech Engn & Appl Mech, Philadelphia, PA 19104 - USA

• Document type: Journal article
• Source: CHEMOSENSORS; v. 8, n. 1 MAR 2020.
• Web of Science Citations: 0

Abstract

An electronic tongue (e-tongue) is a multisensory system usually applied to complex liquid media that uses computational/statistical tools to group information generated by sensing units into recognition patterns, which allow the identification/distinction of samples. Different types of e-tongues have been previously reported, including microfluidic devices. In this context, the integration of passive mixers inside microchannels is of great interest for the study of suppression/enhancement of sensorial/chemical effects in the pharmaceutical, food, and beverage industries. In this study, we present developments using a stereolithography technique to fabricate microfluidic devices using 3D-printed molds for elastomers exploring the staggered herringbone passive mixer geometry. The fabricated devices (microchannels plus mixer) are then integrated into an e-tongue system composed of four sensing units assembled on a single printed circuit board (PCB). Gold-plated electrodes are designed as an integral part of the PCB electronic circuitry for a highly automated platform by enabling faster analysis and increasing the potential for future use in commercial applications. Following previous work, the e-tongue sensing units are built functionalizing gold electrodes with layer-by-layer (LbL) films. Our results show that the system is capable of (i) covering basic tastes below the human gustative perception and (ii) distinguishing different suppression effects coming from the mixture of both strong and weak electrolytes. This setup allows for triplicate measurements in 12 electrodes, which represents four complete sensing units, by automatically switching all electrodes without any physical interaction with the sensor. The result is a fast and reliable data acquisition system, which comprises a suitable solution for monitoring, sequential measurements, and database formation, being less susceptible to human errors. (AU)

• FAPESP's process: 15/14836-9 - 3D printing technology application for microfluidic developments
• Grantee: Maria Luisa Braunger Fier
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 17/06985-0 - Distinct 3D printing technologies applied in microfluidic devices and electronic tongues
• Grantee: Maria Luisa Braunger Fier
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 14/50869-6 - INCT 2014: on Organic Electronics
• Grantee: Roberto Mendonça Faria
• Support Opportunities: Research Projects - Thematic Grants