Large-Scale Integration of All-Glass Valves on a Microfluidic Device.

Yaxiaer Yalikun,Yo Tanaka

doi:10.3390/mi7050083

Abstract

In this study, we developed a method for fabricating a microfluidic device with integrated large-scale all-glass valves and constructed an actuator system to control each of the valves on the device. Such a microfluidic device has advantages that allow its use in various fields, including physical, chemical, and biochemical analyses and syntheses. However, it is inefficient and difficult to integrate the large-scale all-glass valves in a microfluidic device using conventional glass fabrication methods, especially for the through-hole fabrication step. Therefore, we have developed a fabrication method for the large-scale integration of all-glass valves in a microfluidic device that contains 110 individually controllable diaphragm valve units on a 30 mm × 70 mm glass slide. This prototype device was fabricated by first sandwiching a 0.4-mm-thick glass slide that contained 110 1.5-mm-diameter shallow chambers, each with two 50-μm-diameter through-holes, between an ultra-thin glass sheet (4 μm thick) and another 0.7-mm-thick glass slide that contained etched channels. After the fusion bonding of these three layers, the large-scale microfluidic device was obtained with integrated all-glass valves consisting of 110 individual diaphragm valve units. We demonstrated its use as a pump capable of generating a flow rate of approximately 0.06–5.33 μL/min. The maximum frequency of flow switching was approximately 12 Hz.

Highlights

An on-chip microfluidic valve is an indispensable component for miniaturization in chemistry or biology to produce a “lab-on-a-chip” or a micro-total analysis system (μ-TAS)
The integration of a large number of valves in the lab-on-a-chip or μ-TAS increases the flexibility of dynamic flow control, and increases the number of samples that can be handled in simultaneous analysis and synthesis processes [2,3]
We used focused electrical discharging method (FEDM) to fabricate 220 50-μm-through-holes in 110 1.5-mm-diameter shallow chambers fabricated by wet etching on a hard glass slide as valve chambers

Summary

Introduction

An on-chip microfluidic valve is an indispensable component for miniaturization in chemistry or biology to produce a “lab-on-a-chip” or a micro-total analysis system (μ-TAS). Several different materials are used to fabricate on-chip monolithic membrane valves independently They are silicon [10], polymers (electroactive polymer [11], polydimethylsiloxane (PDMS) [2,3,6,12,13,14], plastic [15], hydrogel [16], and glass [17,18]. Among these materials, because PDMS is the most biocompatible, has a simple fabrication process, and is easy to Micromachines 2016, 7, 83; doi:10.3390/mi7050083 www.mdpi.com/journal/micromachines use, it is widely used for large integrated on-chip microfluidic devices.

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Conclusion