Solvent-assisted polymer micro-molding

The micro-molding technology has played an important role in fabrication of polymer micro-patterns and development of functional devices. In such a process, suitable solvent can swell or dissolve the polymer films to decrease their glass transition temperature (Tg) and viscosity and thereby improve flowing ability. Consequently, it is easy to obtain the 2D and 3D patterns with high fidelity by the solvent-assisted micro-molding. Compared with the high temperature molding, this technology overcomes some shortcomings such as shrinking after cooling, degradation at high temperature, difficulty in processing some functional materials having high Tg, etc. It can be applied to making patterns not only on polymer monolayers but also on polyelectrolyte multilayers. Moreover, the compression-induced patterns on the multilayers are chemically homogenous but physically heterogeneous. In this review, the controlling factors on the pattern quality are also discussed, including materials of the mold, solvent, pressure, temperature and pattern density. Supported by the National Natural Science Foundation of China (Grant No. 20774084), State Key Development Program of Basic Research of China (Grant No. 2005CB623902) and National Science Fundation for Distinguished Young Scholars (Grant No. 50425311)