Binder-jet printing and pressure-controlled infiltration for fabrication of high-temperature, low-dead-volume microfluidic interfaces

• All-metal, low-dead-volume interface between BJ printed microchannel and SS capillary. • Pressure-controlled infiltration bonds interface without clogging channels. • Interfaces withstand >100 PSI and thermal cycling to 350 °C without leaking. • SEM cross-sections reveal smooth connections with minimal dead volume. Interfacing is a consistent weak point in the manufacturing of microscale gas chromatography columns. Current techniques for interfacing with microfluidic systems often degrade under high temperatures and thermal cycling and suffer from dead volumes. To address these challenges, we fabricated all-metal interfaces that connect 3D-printed microchannels (500 µm diameter) to industry-standard stainless-steel (SS) capillaries. Our fabrication process uses SS binder-jet printing and bronze infiltration to fuse the capillary to the printed part and reduce dead volumes at the interface while utilizing pressure control to prevent the infiltrant from filling the channel or capillary. These interfaces withstood pressures greater than 100 PSI and showed no leakage after thermal cycling to 350 °C. Cross-sections of the interfaces show smooth connections between the channel and capillary with minimal dead volume.