Low budget, high tech: Microfluidics device out of a $50 plotter!

Building and using low budget but high tech devices at home is a main motivation behind hacking. A Harvard Chemistry Research Group now created a microchannel producing device using a Hewlett Packard 7550A Graphics Plotter (see some eBay prices) to perform a diagnostic protein assay with it amongst others. /See my SciFoo microfluidics coverage./

According to the current Nature by Tim Lincoln:

“The system works like this. By replica moulding, the pens of the plotter are replaced with PDMS versions that can deliver various types of ‘ink’. The purpose of the ink, when cured, is to create channels in a filter-paper substrate, and after experimenting with the possibilities Bruzewicz et al. found that a syrupy mixture of 3:1 PDMS:hexane did just fine. Having chosen the appropriate paper, the trick then is to use the plotter to draw channel shapes, with the PDMS syrup penetrating the full depth of the paper to create water-tight chambers in various patterns.”

Hardware-Software Specs from the supporting information:

Computer.
• Computer: Dell Dimension 4100, Pentium III Processor (1 GHz)
• Plotter: Hewlett Packard 7550A Graphics Plotter
• Operating System: OpenSuSE Linux 10.1, Novell Corporation. Available for free download
• Additional Software:
1. Inkscape – vector drawing program, for design of channels. Included in OpenSuSE, also
available for free.

The HP Computer Museum highlights this particular plotter:

7550A pen plotter (1984). Computers are not very interesting to observe in action (many people say the same is true of computer collectors). In the relatively short history of the industry, the only products of exception have been the pen plotters. These mechanical marvels are nothing less than fascinating to watch. Although pen plotters were made well into the mid 1990s, the 7550 was the best ever. The 7550 combines blinding speed (maximum 6g acceleration) with a cut sheet feeder to make it the most productive plotter ever made. These machines are still commonly available on the second hand market.