Lithographic microfabrication of biocompatible polymers for tissue engineering and lab-on-a-chip applications

In this work, a combination of Direct Laser Writing (DLW), PoliDiMethylSiloxane (PDMS) soft lithography and UV lithography was used to create cm- scale microstructured polymer scaffolds for cell culture experiments out of different biocompatible materials: novel hybrid organic-inorganic SZ2080, PDMS elastomer, biodegradable PEG-D A-258 and SU-8. Rabbit muscle-derived stem cells were seeded on the fabricated different periodicity scaffolds to evaluate if the relief surface had any effect on cell proliferation. An array of microlenses was fabricated using DLW out of SZ2080 and replicated in PDMS and PEG-DA-258, showing good potential applicability of the used techniques in many other fields like micro- and nano- fuidices, photonics, and MicroElectroMechanical Systems (MEMS). The synergetic employment of three different fabrication techniques allowed to produce desired objects with low cost, high throughput and precision as well as use materials that are difficult to process by other means (PDMS and PEG-DA-258). DLW is a relatively slow fabrication method, since the object has to be written point-by-point. By applying PDMS soft lithography, we were enabled to replicate laser-fabricated scaffolds for stem cell growth and micro-optical elements for lab-on-a-chip applications with high speed, low cost and good reproducible quality.