Biomedical subjects

C O'Mathuna

Publications and source records attributed to C O'Mathuna.

2 recordsLinked to original sources

PubMed2001

Rapid fabrication of microfluidic devices in poly(dimethylsiloxane) by photocopying.

A very simple and fast method for the fabrication of poly(dimethylsiloxane) (PDMS) microfluidic devices is introduced. By using a photocopying machine to make a master on transparency instead of using lithographic equipment and photoresist, the fabrication process is greatly simplified and speeded up, requiring less than 1.5 h from design to device. Through SEM characterization, any micro-channel network with a width greater than 50 microm and a depth in the range of 8-14 microm can be made by this method. After sealing to a Pyrex glass plate with micromachined platinum electrodes, a microfluidic device was made and the device was tested in FIA mode with on-chip conductometric detection without using either high voltage or other pumping methods.

Journal Article↗

PubMed2001

Ion chromatography on-chip.

On-chip separation of inorganic anions by ion-exchange chromatography was realized. Micro separation channels were fabricated on a silicon wafer and sealed with a Pyrex cover plate using standard photolithography, wet and dry chemical etching, and anodic bonding techniques. Quaternary ammonium latex particles were employed for the first time to coat the separation channels on-chip. Owing to the narrow depths of the channels on the chip, 0.5-10 microm, there were more interactions of the analytes with the stationary phase on the chip than in a 50-microm I.D. capillary. With off-chip injection (20 nl) and UV detection, NO2-, NO3-, I-, and thiourea were separated using 1 mM KCl as the eluent. The linear ranges for NO2- and NO3- are from 5 to 1000 microM with the detection limits of 0.5 microM.

Chromatography, Ion Exchange↗