The last technical period of the project micromole has been marked by intensive testing, integration work and performance improvements of 1) a system that includes all modules, with the exception of the energy harvesting module and the chemical sensing module, and 2) a prototype of the chemical sensing module.
During its 42 months, the consortium managed to fully integrate and test a prototype consisting of three rings, a gateway and a crawler robot. The first two rings contain a pH sensor and a conductivity sensor, while the third ring contains a sampling module and an optical communications module for allowing data transmission to a gateway device installed far away. All rings are equipped, in addition, with an energy management module, additional batteries (in place of the energy harvesting module), a main controller and a radio module.
The micromole system is able to periodically measure pH and conductivity of the sewage flow and to trigger the sampling module for physical evidence gathering, whenever the pH and conductivity measurements abruptly change as to match
values that can be correlated with an ATS waste spill in the sewage. The sampling module is able to collect up to three 1.5mL physical samples of the sewage flow in 15 seconds. The average time elapsed since an abrupt change in pH or conductivity
is identified by the first two rings to the moment when the sampling module in the third ring starts collecting evidence is on average 350 milliseconds.
The crawler robot allows mounting the ring device remotely in sewer pipes of no less than 250mm in diameter. The crawler robot is capable of transporting two ring devices at a time, reducing the total installation time. Thanks to the crawler robot and the usage of optical communications, the system can be mounted 200 meters away from the suspected place through a manhole, in an unnoticed manner.
In addition, the consortium was able to achieve the implementation and testing of two chemical sensor module prototypes, both of which includes the ASIC, the transducers, the active fluidic system and the MIPs as recognition element. The integration of the chemical sensor was not completely achieved within the fully integrated micromole ring prototype due to problems in the data analysis. The harsh and changing conditions in the sewage and the time needed for correct sample
identification within the chemical sensor hindered the data analysis tasks of the consortium and prevented the consortium -within the time frame of the project- from designing an efficient and general mechanism for discerning the presence of the substances based on the output data of the chemical sensor.
During the last 18 months of the project, five testbed sessions were organized (three in KWB and two in Legionowo), where all partners had the opportunity to test different prototypes and detection principles in real conditions and verify the correct functionality of the full system. Following the recommendations of the EC reviewers, the consortium stopped the development of the energy harvesting device and the acoustic communication module in the last period.
