Abstract:

A cheap PMMA was chosen as the substrate instead of expensive silicon or glass,and a 248 nm excimer laser with flexible and auto character replaced complex lithography as a new fabrication technique.  A PMMA(48 mm×67 mm×1 mm) based micro flow through PCR chip with 20 cycles was fabricated at 19 kV and 18 mm/min excimer laser parameters.  The section of the microchannel was trapezoid,and its bottom surface roughness was less than 0.5 μm.  The microchannel had a width of 104 μm,a depth of 56 μm,and a length of 2 060 mm. It cost about 110 min to finish the total length.  Then the chip was bonded together with another cover chip at 105 ℃,160 N and 20 min parameters.  It could endure 0.85 MPa pressure and seal micro fluid well after sample injection experiment.  In the end,the chip was integrated via the temperature control system.  Three micro PID temperature controllers were chosen to control the temperature and gained ±0.2 ℃ temperature control precision.  The temperature grads between the three temperature zones were 16.5  and 22.2 ℃,respectively.  Finally 170 bp DNA fragments was amplified by using this chip.

Key words: PMMA; Micro flow through PCR chip; Excimer laser