Flore Rembert (ISTO) will present her research developments on A microfluidic chip equipped for geoelectrical monitoring of the critical zone processes.
We miniaturize the geoelectrical acquisition using advanced microfabrication technologies to inves-
tigate coupled processes in the critical zone. We focus on the development of the complex electrical
conductivity acquisition with the spectral induced polarization (SIP) method on a microfluidic chip,
consisting of a straight channel equipped with four aligned electrodes. This approach at the microm-
eter scale allows working in well-controlled conditions, with real-time monitoring by high-speed and
high-resolution microscopy. It grants the direct observation of the subsurface microscopic reactive
transport processes occurring in the critical zone. First, we show the feasibility and accuracy of
SIP measurements on brines of different salinities. Then, we monitor the dissolution of pure calcite.
We highlight the strong correlation between SIP response and dissolution through image processing.
These study’s results demonstrate that the proposed technological advancement will provide further
understanding of the critical zone processes through SIP observation.