Numerical study on the de-molding behavior of 2D PMMA nanochannles during hot embossing process

Hot embossing of polymethyl methacrylate (PMMA) sheet is an emerging method for fabrication of two dimensional (2D) nanochannels with low cost and high replication precision. However, the de-molding step which influences the replication precision of the final 2D PMMA nanochannels has not yet been studied systematically. In this work, the effect of the de-molding angle, de-molding temperature and friction coefficient between the 2D silicon nano-mold and the PMMA sheet on the maximum local stress in the 2D PMMA nanochannels was studied by finite element method. The results show that the maximum local stress appears in the period of 0.8–0.9 s, which indicates that the damage of 2D PMMA nanochannels may be more likely to occur at the end of the de-molding step. To separate the 2D silicon nano-mold and the PMMA sheet without nanochannels damage, the following processing parameters are suggested: de-molding angle smaller than 0.5°, de-molding temperature of 85 °C and anti-sticking treatment on the surface of the nano-mold.