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Process Date: February 2003
CO2 lasers have great potential for producing polymer microfluidic channels in very short manufacturing cycle times. Microfluidic channels are sandwich bonded together to create micro fluidic tubes, which allow the transportation of minuscule amounts of liquid. These microfluidic systems are in various kinds of biochemical analysis such as waste water monitoring or in medical applications such as drug delivery and point-of-care diagnostics.1
The material shown in the photos to the left is a 1/8"-thick sheet of PMMA [poly(methyl methacrylate)]. Using Synrad's 48-1 CO2 laser, a 100-micron wide by 100-micron deep channel was scribed into the surface. Power was set to 6W and the FH marking head moved the laser beam across the material at 5 inches per second (IPS). During the initial scribing trial, excess material built up along the edges of the channel and trapped gaseous bubbles formed along the channel’s base. Subsequent trials proved that cooling the PMMA in liquid nitrogen just before scribing remedied both of the anomalies. The small amount of material build-up remaining on the edges of the channel is thought to assist in the structural sealing of the channels during the bonding process.
References:
1 Henning Klank, Jorg P. Kutter and Oliver Geschke. The Royal Society of Chemistry, 2002, 242-246.
This 100-micron wide channel was made using only 6W of power on a sheet of super-cooled PMMA.
Enlarged view of the scribed channel.
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