Simple microfabrication method of glass plate using high-viscosity photoresist for micro analytical systems

Abstract

We have developed a method for microfabrication on a glass plate by photolithography using a high-viscosity photoresist as an etching mask. This fabrication method does not require the coating and etching of thin metal (Au/Cr) layers on the glass; therefore, the use of this photoresist has made simple and rapid microfabrication possible in a general laboratory. By this method, the etching time of glass was prolonged by as much as 100 min (about 100 µm depth) in an ammonium hydrogenfluoride etchant using an 800 cP photoresist and a borosilicate glass plate. The fabricated glass template was of even quality, and the precision of the reproduction of the glass plate was calculated (e.g., 0.74% RSD, n = 3, 2 pt). A relief with a minimum width of 81.5 µm was fabricated within several hours. We used the fabricated glass for the template of a polymer microchip for environmental analysis. The fluorometric analysis on the PDMS microchip was well demonstrated. The calibration curve of sulfite showed good linearity (R2 = 0.998). Moreover, an environmental sample was analyzed utilizing this microchip.