In this method, the applied solvent diffuses across the polymer interface and dissolves the polymer chains making them mobile. The polymer substrates are compressed and as the solvent evaporates, the induced mobile chains are entangled in each other at the interface and create a strong bonding force . In order to avoid deformation of the polymer by the solvent, it is carried out at very low solvent concentrations, which increases the required bonding time 105 . Solvent bonding is usually stronger when it is used for bonding layers with the same material combinations and when it is integrated with thermal bonding .