Micro-fluidic devices are widely used today in the areas of medical diagnostics and drug research, as well as for
applications within the process, electronics and chemical industry. Microliters of fluids or single cell to cell interactions
can be conveniently analyzed with such devices using fluorescence imaging, phase contrast microscopy or spectroscopic
techniques.
Typical micro-fluidic devices consist of a thermoplastic base component with chambers and channels covered by a
hermetic fluid and gas tight sealed lid component. Both components are usually from the same or similar thermoplastic
material. Different mechanical, adhesive or thermal joining processes can be used to assemble base component and lid.
Today, laser beam welding shows the potential to become a novel manufacturing opportunity for midsize and large scale
production of micro-fluidic devices resulting in excellent processing quality by localized heat input and low thermal
stress to the device during processing.
For laser welding, optical absorption of the resin and laser wavelength has to be matched for proper joining. This paper
will focus on a new approach to prepare micro-fluidic channels in such devices using a thermal transfer printing process,
where an optical absorbing layer absorbs the laser energy. Advantages of this process will be discussed in combination
with laser welding of optical transparent micro-fluidic devices.
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