2, Massachusetts Institute of Technology, Boston, Massachusetts, United States
3D printing of microstructures with controllable surface wettability and optical properties is valuable to both fundamental research and practical applications. Such 3D structures are envisioned for microfluidic devices, micro electro-mechanical devices, optical components, biomedical and tissue engineering applications. However, poor optical transparency and need of additional surface modification step are obstacle in printing multi-functional 3D structures. Here, we propose an in-situ photoinitiated copolymerization approach to print multifunctional high resolution 3D microstructures using micro stereolithography. The use of rationally designed copolymerization approach enables us to tailor the wetting behavior (hydrophilic/phobic), while the appropriate choice of photoinitaioter and cross-linker aids in tuning the optical transparency of the 3D printed structures. The versatility of this approach is the use of monomers with hydrophilic and oleophilic moieties to print the structures ranging from very high to very low surface energy, which avoids the interface mismatch after surface modification for optical microscopy imaging. This optimized approach will help us in prototyping submicro-or micro-models with complex geometries and well defined wettability.