A novel bonding method for fabrication of PMMA nanofluidic chip with low deformation of the nano-trenches

All PMMA-based nanofluidic chips are becoming increasingly important for biological and medical applications. To fabricate PMMA nanofluidic chips, the open nano-trenches should be sealed by thermal bonding method. However, the present thermal bonding method suffers from high deformation of nano-trenches due to PMMA softening near glass transition temperature. In this work, a novel bonding technique, based on acetone and ethanol (v:v, 8:2) treatment, is developed to adjust the Young’s modulus of PMMA in its surface layer. By optimizing nanoimprinting and bonding process, PMMA nanofluidic chip was fabricated without undesired nano-trench deformation. The integrity of the enclosed PMMA nanofluidic system was verified by a fluorescence filling experiment.