Extraction of Soil Solution into a Microfluidic Chip

Collecting real-time data on physical and chemical parameters of the soil is a prerequisite for resource-efficient environmentally sustainable agriculture. For continuous in situ measurement nutrients such as nitrate or phosphate, lab-on-chip approach combined with wireless remote readout promising. this purpose, solution, i.e., water nutrients, needs to be extracted into microfluidic chip. Here, we present soil-solution extraction unit based combining porous ceramic filter channel 12 µL volume. The chip was fabricated from polydimethylsiloxane, had size 1.7 cm × 0.6 cm, bonded glass substrate. A hydrophilic aluminum oxide approximately 37 Vol.-% porosity an average pore 1 µm integrated at inlet. Soil successfully three types soil—silt, garden soil, sand—by creating suction pump other end channel. rate 15 moisture 1.4 µL/min. amount investigated 30 min intervals different levels. sand, started around 10 moisture. Silt showed highest water-holding capacity, starting 13 Vol.-%.