Mircorfabrication of microfluidic channels on soda-lime glass

This paper describes the fabrication procedure of microfluidic channels on soda-lime glass with a polydimethylsiloxane (PDMS) elastomer seal. The microchannel fabrication process is based on microfabrication technology and includes the followings: spinning the positive photoresist AZ-4620 on the soda-lime glass, exposing and developing the photoresist, etching the microchannels using a buffered oxide etchant (BOE), and PDMS bonding. PDMS bonding to the glass substrate was achieved using oxygen plasma to change the surface characteristics of PDMS from hydrophobic to hydrophilic, thus enabling the PDMS and glass surfaces to bond by covalent forces. Scanning electron microscopy (SEM) photos peel tests, and fluid flow experiments demonstrate the integrity of the PDMS and glass bonds. Due to the excellent optical properties of the PDMS elastomer, these microfluidic chips with microchannels can be used to detect luminescence and fluorescence phenomena in bio-medical and bio-chemical applications occurring within the microchannels.