| Abstract [eng] |
Polymer structures of micrometer scale reacts differently to ambient conditions – they can contract or expand depending on liquid they are submerged into. By using this unique feature and by employing Moiré pattern a polymeric chemical microsensor was designed. The aim of this work was designing and manufacturing a polymeric chemical microsensor, its integration into glass micro-channel structures and highlighting integration problems. All the experiments were performed using Yb:KGW Pharos laser (by Light Conversion) with pulses at 1030 nm wavelength and 320 fs duration. This wavelength was used to fabricate structures in fused silica. For polymerization a non-linear second harmonic conversion was used to achieve 515 nm. Lenses with numeric aperture (NA) of 0.4 and 1.4 were used for making structures in fused silica and making structures of photopolymer respectively. Positioning system consisted of three Aerotech translation stages for x, y and z axes. Both subtractive and additive processes were performed with one laser system. It was concluded that by using the same 2 $\mu$J pulse energy, while fabricating micro-channels in fused silica, one can achieve either relatively flat micro-channel surface (approx. 300 nm roughness) or some periodic structures on the surface of micro-channel. This can be selected by differing light polarization, due to modification sensitivity to it. It was concluded that chemical-polymer sensor is expanding in 4-methyl-2-pentanone and ethanol solutions (moiré patterns indicated expanding period) and contracts in water (moiré patterns indicated diminishing period). A polymeric chemical microsensor that is sensitive to its ambient conditions was shown in this work and its viability in micro-fluidic application was stipulated. A concept of base layer formation on additional platforms was suggested for further sensor improvement. This concept should diminish the negative effects of micro-channel non-uniformity. |
