Error Analysis for Microchannels Fabrication using Photochemical Machining on Brass

Abstract

AbstractThe microchannels are broadly used for various applications in Lab on a chip (LOC) and Micro Total Analysis Systems (µ-TAS). The fabrication of precise microchannel is a crucial task. Soft lithography is one of the widely preferred processes for microchannel fabrication and the mold required in soft lithography can be fabricated using photochemical machining (PCM).The accuracy of the fabricated components in PCM depends upon the photo tool and the cumulative error. This paper presents the error analysis for fabrication of microchannels using photochemical machining on brass material. In PCM, the etchant concentration and etching time are kept constant. The etchant temperature is varied as 45, 50 and 55 °C. The microchannels with three widths, viz. 200 µm, 250 µm and 300µm are fabricated at the considered temperatures using PCM. There is deviation between desired microchannel width and the width of fabricated microchannel using PCM which is termed as error and is required to be analyzed. The performance of PCM process is measured as the percentage error between drawing and the photo tool, percentage error between specimens and photo tool and the cumulative percentage error. It is observed that the errors enhance with increase in temperature. The observed average cumulative error is 9.46%. 13.54 and 18.11% for temperatures of 45 °C, 50 °C and 55 °C, respectively. Based on the study, it is recommended that the photo tool size is required to be reduced in proportion of the cumulative percentage error analysis in order to have the desired size on the specimens.KeywordsError analysisPhotochemical machiningBrassEtchant temperaturePhoto tool