Efficient Fabrication of Single-Unit Hybrid Paper/PDMS Microfluidics with Controllable Bonding Strength for Oil/Water Separation and Gradient Generator

This work describes a novel fabrication procedure for single-unit paper/PDMS microfluidic platforms with controllable bonding strength reaching up to 970 kPa, enabling highly efficient applications in two-phase oil/water separation and gradient generation. All tested cases showed excellent performance: (1) A continuous two-phase flow of oil/water droplets was completely separated with 100% purity and an over 80% recovery rate; (2) By varying flow rates and changing paper patterns, different gradient profiles could be generated with full control of concentration levels and transition types.