Robust multi-parameter sensing probe for water monitoring based on ALD-coated metallic micro-patterns

We report on a multi-sensing probe for water network monitoring enabling simultaneous measurements of water electrical conductivity, flow-rate and temperature. A very simple fabrication process is used where all physical sensors are obtained only from micro-patterning of glass, combining platinum, gold. Further coating using Atomic Layer Deposition (ALD) is achieved for the purpose of reducing both electro-erosion and biofouling, while keeping the sensor's electrical and thermal functionalities. This is critical for long-term reliability of sensors immersed in water. The lateral size of each sensing elements does not exceed a few 100µm. This small footprint allowed implementing a redundancy strategy on the chip, not only for reliability purposes but also to accommodate for different measurement ranges based on scalable designs.