Fluidic and Electrical Modular Interfacing: A modular approach to micro total analytical systems and micro gas chromatography

Micro total analytical systems (μTAS) or lab-on-chip devices have emerged as powerful, miniaturized platforms for (bio)chemical analysis and engineering. They drastically reduce sample-reagent volume requirements, accelerate processing times, and enable automation, making them ideal for in-situ applications. However, integrating fluidic, electrical, and mechanical components within μTAS remains challenging due to design constraints, manufacturing complexities, diverse functionalities, demanding operating conditions, and incompatible maintenance procedures, ultimately hindering the widespread adoption of μTAS. Here, we present the standardized Fluidic and Electrical Modular Interfacing (FEMI) architecture, a scalable integration approach that combines modularity with the performance of monolithic integration. FEMI facilitates easy-to-remove, gas-tight, heat-resistant, low-dead-volume fluidic connections for microfluidic chips with side ports alongside detachable electrical interfaces by packaging the components as removable cartridges. To demonstrate its potential, we developed FEMI-GC, a micro gas chromatography (μGC) system for detecting trace levels of volatile organic compounds (VOCs). FEMI-GC includes a micro-preconcentrator (μPC) for sample preconcentration, a micro-separation column (μSC) for sample separation, and an off-the-shelf photoionization detector (PID) for compound detection, all within a compact footprint (3.75 L, 2 kg). It also features 3D-printed needle valves for precise flow control and a micro-fluidic routing board (μFRB) to direct flows through various stages. The interfacing could withstand operating temperatures >275 ˚C and pressures > 40 psi, enabling FEMI-GC to detect VOCs with a detection limit of 0.73 ppb and offer a tested detectable dynamic range of >50,000x. This work establishes FEMI as a scalable approach for allowing the rapid development and adoption of robust modular μTAS.