Photocurable resin-silica composites with low thermal expansion for 3D printing microfluidic components onto printed circuit boards

Fabricating microfluidics directly onto a printed circuit board (PCB) is a promising method to produce integrated systems. Here, we applied stereolithography (SLA) to 3D print microfluidic components directly onto PCBs. Current SLA resins suffer from significant thermal expansion, which leads to adhesion issues during temperature cycling. Photocurable composites with a low coefficient of thermal expansion (low-CTE composites) were developed to address this bonding issue by minimising the interfacial thermal stress. The resulting low-CTE resin-silica composites robustly bond to PCBs and can be used for fabricating PCB-based microfluidics in chemical engineering or thermal management (e.g., chemical reaction, 3D packaging, or heat removal devices).