Low cost wireless passive microsensors for the detection of hazardous compounds in water systems for control and monitoring

In the present work, we studied the design and fabrication of low cost passive microsensors for measuring hazardous compounds. The sensors were fabricated with low cost and biocompatible materials, making them suitable for several industries and applications. These wireless sensors are small enough to be placed inside pipes and recipients of more than 1 cm in diameter. Sensors were tested with air, distilled water, acetic acid, pyridine, N,N-dimethylformamide and butanol, presenting high accuracy, repeatability and reproducibility among substances and sensors. The sensors showed a high resistance to corrosion and oxidation after cycling operation. The whole measuring system, that included the sensor and the coupling antenna, proved to be suitable for measuring low dielectric constant and low volatility compounds presenting an average standard deviations in the detection of any compound of 4.23%.