Robust Multi-Parameter Sensing Probe for Water Monitoring Based on ALD-Coated Metallic Micro-patterns and Carbon Nanotube Printing

IEEE NEMS 2016 - The 11th Annual IEEE International Conference on Nano/Micro Engineered and Molecular Systems, Matsushima Bay, JAPON, 17-/04/2016 - 20/04/2016; We report on a multi-sensing probe for water network monitoring enabling simultaneous measurement of water electrical conductivity, flow-rate, temperature and pH. 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. Carbon nanotubes are then inkjet-printed last for the pH sensor. 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.