Ultrasonic welding for the rapid integration of fluidic connectors into microfluidic chips

We introduce a variety of biocompatible fluidic connectors that can be integrated into microfluidic chips by ultrasonic welding. Commercially available barbed fittings and dispensing needles with Luer lock fittings were integrated between two chip components ensuring a fluidic in-plane contact. In addition, straight Luer lock fittings in combination with ultrasonic hot embossing, 3D printed thermoplastic connectors with Luer lock and barbed fittings were integrated out-of-plane. The integration was successful without clogging any fluidic channels. Depending on the connector type, the pressure tightness differs. Dispensing needles showed the lowest pressure tightness of only 1.14 bar. However, all other connector types were pressure tight to at least 3.75 bar. The main advantage of the integration technique of ultrasonic welding is the rapid implementation of individual connectors adapted to the required situation—for prototypes as well as for large-scale production. Moreover, multiple connectors can be integrated simultaneously in just one single step. This provides a user-friendly and stable connection of commonly used connector types such as barbed or Luer lock fittings for microfluidic applications.