Water glass bonding for micro-total analysis system

We used water glass solution for bonding two glass wafers on which electrodes and a micro-channel were fabricated. This bonding technique makes possible to bond two glass wafers without concerning the problem of surface roughness. We evaluated many properties of the water glass bonding for using micro-chemical analysis, such as, effect of bond temperature on bond strength, thickness of bonding layer dependence on applied pressure during bonding, and so on. Because of high content rate of sodium in water glass, we evaluated cleaning effect to decrease sodium dissolution from bonding layer. Additionally, we studied the effect of the pH of solutions on bond strength. By using this technology, we made a micro-electrochemical chip as one of applications and identified an oxygen evolution current without break down of the chip. We show this bonding technique is very useful to make a micro-chip. (C) 2002 Elsevier Science B.V. All rights reserved.