Novel chemical approach to achieve advanced soft lithography by developing new stiffer, photocurable PDMS stamp materials

Recent advances in microfabrication technology allow us to develop a number of novel devices with high performance. In microfabrication technology, a new development, 'soft lithography', is widely used by making stamps, molding, and microcontact-printing due to the low cost and easy processability. The resolution of soft lithography significantly relies on the performance of stamping materials. However, pattern transfers using commercially available PDMS stamp materials often end up with mechanical failures such as collapse or sag due to their low physical stiffness. Additionally, most of those commercial PDMS materials are thermally curable systems, which results in significant thermal deformations. These limitations have motivated us to start this work, which demonstrates a 'chemical approach' to overcome those limits by developing new stiff, photocurable PDMS stamp materials with attached designed functionalities. Molecular modification of PDMS materials results in advanced soft lithography, which produces enhanced physical toughness, lower polymerization shrinkage, and photopatterning capability.