The aim to provide preventive healthcare and high quality medical diagnostics and
treatment to an increasingly ageing population caused a rapidly increasing demand for
point-of-care diagnostic devices. Disposables have an advantage over re-usable units
as cross-contamination is avoided, no cleaning and sterilising of equipment is required
and devices can be used out of centralised laboratories. To remain cost-effective, costs
for disposables should be kept low. This makes polymer materials an obvious choice.
One method for the realisation of fluidic micro devices is the stacking of several
layers of microstructured polymer films. Reel-to-reel manufacturing is a promising
technique for high-volume manufacturing of disposable polymer bio-analytical
devices. Polyethylene terephthalate (PET) and cycloolefin copolymer (COC) were
selected as suitable polymer substrate materials and polydimethyl siloxane (PDMS) as
membrane layer.
Bonding of polymer films with the help of adhesives carries the risk of channel
blocking. Despite this drawback, no other method of bonding PDMS to a structural
layer could be identified. Bonding with solvents avoids channel blocking issues, but
adversely affects biocompatibility.
Thermal diffusion processes enable bonding of COC and PET without the use of any
auxiliary material. The extensive process times requires for thermal diffusion bonding
can be considerably shortened by pre-treating the material with plasma or UV
exposure. Welding with the use of a laser energy absorbing dye was demonstrated to
be particularly suitable for selective bonding around channels and reservoirs.
None of the assessed bonding methods provide a generic solution to all bonding
applications. Instead, the selection of an appropriate technique depends on the
intended application and the required level of biocompatibility. Since this selection
has implications on the feasibility and reliability of microfluidic structures on the
device, design rules which ensure design for production have to be established and
followed.
| Identifer | oai:union.ndltd.org:ADTP/216666 |
| Date | January 2007 |
| Creators | Garst, Sebastian, n/a |
| Publisher | Swinburne University of Technology. |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
| Rights | http://www.swin.edu.au/), Copyright Sebastian Garst |
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