Carbon Nanotube Inkjet Printing Based Resettable Sensor for Online Scale Monitoring

In this paper, a new type of sensor and associated system for complete online monitoring of scale deposition with great accuracy and reliability is fabricated and characterized. The system is based on carbon nanotubes (CNTs), which have unique sensing/electronic properties along with physical and chemical stability in corrosive and hostile environments required for the oil and gas application. CNTs inkjet printing technique is used to fabricate the CNTs sensor. The sensitivity of the films, real time monitoring of brine solution, stability of the films in various solvents and fluids and the ability of setting and resetting of the sensor are studied. The results of these studies indicate that adding of one brine solution on the surface of the CNTs inkjet printing increases the resistance from 0.50 kΩ to 1.50 kΩ. The CNTs inkjet printing sample is found to be stable even after 48 hours of soaking the whole sample in DI-water. This sensor not only shows good sensing response for detection of the deposition of brine, but can also be easily reset back many times by just wash it with DI-water. This simple sensor is ideally suited for real time monitoring and the response time of the film is found to be from 15–30 s.