Articles techniques et présentations

We present the development of a micro gas generator (see Fig. 01: Schematic of the micro gas generator), engineered to deliver controlled analyte pulses in the ppb–ppm range via permeation through porous polymer membranes. The device incorporates four micro‑reservoirs embedded within a sealed glass body, each capped with a temperature‑activated permeable membrane. Permeation rates are tunable through temperature control, membrane thickness, membrane area, and membrane material processing. The project integrates device fabrication with a multiscale COMSOL Multiphysics modeling framework to guide design decisions and predict operational performance. Continuum‑scale simulations employ the Transport of Diluted Species in Porous Media interface with temperature‑dependent transport parameters to rapidly evaluate permeation behavior across broad operating conditions. Pore‑scale simulations use Darcy and Brinkman formulations from the Subsurface Flow Module to resolve flow and species transport within porous structures featuring adjustable permeability, pore‑size distributions, and anisotropy. This dual‑scale approach enables direct comparison between effective‑medium predictions and pore‑resolved transport, providing quantitative insight into membrane behavior. We will present parametric sweeps across temperature (25°C–120 °C), analyte identity (ethanol, acetone), and PDMS membrane properties that generate permeation‑rate maps identifying operating windows for achieving target fluxes in the 10⁻⁹ to 10⁻⁶ mol m⁻² s⁻¹ range. These results directly inform membrane selection, device geometry, and heater‑control strategies during fabrication. A forthcoming stage integrates SEM and AFM membrane images via COMSOL’s Image‑to‑Geometry workflow to construct morphology‑accurate pore networks for simulation. The combined modeling–fabrication workflow establishes a quantitative foundation for completing a fully functional micro gas generator prototype and for systematically comparing analyte–membrane combinations.