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Low-cost and energy-efficient LTCC sensor/IR-UWB transceiver solutions for sustainable healthy environment

Final Report Summary - SENSEIVER (Low-cost and energy-efficient LTCC sensor/IR-UWB transceiver solutions for sustainable healthy environment)

More than six billion tons of gas pollutants are released to Earth’s atmosphere due to fossil fuels combustion and other industrial processes. Therefore, pollution represents one of the greatest issues of today’s world. Scientists are warning the public that, if the environment were to be continuously polluted in the same manner as during the past decades, we are about to face a disaster of immense proportions. Global warming is a serious issue, but, unfortunately, not the only one. Ocean acidification is continuously increasing as a consequence of the atmosphere’s carbon-dioxide reacting with water. The fresh water availability significantly influences the quality of life and human health. If the soil is polluted by toxic chemicals, garbage or microorganisms – disease carriers, rain and melted snow bring that very same pollution to rivers, lakes and oceans, thus endangering water ecosystems. One of the utmost needs is to provide systematic environment monitoring in all three medium: soil, water and air. Furthermore, efficient sensors able to detect changes caused by the pollutant presence, a system interconnecting those sensors by enabling wireless information transfer among them are also needed. The development and design of such devices and systems represent the main topic and the task of the SENSEIVER project, which actually represents the platform for employment of both, early stage researchers (ESRs) and experienced researchers (ERs), their training and education in leading institutions of the six European countries.

The project brought together three universities, two institutes and two companies from six different European countries:
1. University of Novi Sad, Serbia (which employed the young researchers Aleksandar Pajkanovic-ESR1, Srdjan Ajkalo-ESR2 and Akhil Chandran-ESR3)
2. University of Technology from Vienna, Austria (which employed the young researchers Sasa Toskov-ESR4 and Goran Miskovic-ESR5)
3. Technical University Gheorghe Asachi from Iasi, Romania (which employed Anatolie Iavorschi-ESR6, Nenad Zoric-ESR7, Mariana Sireteanu-ESR8, Jose Francisco Blanco Villalba-ESR9 and Cornelia Lorenz-ER1-ER3)
4. Institute of Electron Technology in Krakow, Poland (which employed Katarina Cvejin-ESR10, Libu Manjakal-ESR11 and Monika Zawadzka-ER4)
5. Institute for Systems Engineering and Computers from Porto, Portugal (which employed Iman Kianpour-ESR12 and Bilal Hussain-ESR13)
6. TES Electronic Solutions company from Stuttgart, Germany (which employed Branislava Milinkovic-ESR14 and Milenko Milicevic-ESR15)
7. North Point Company from Subotica, Serbia (which employed Mitar Simic-ESR16)

Within multidisciplinary projects scientific research is performed in several different areas of science. In the case of SENSEIVER, the results can be divided in four disciplines:
• new materials synthesis;
• design, fabrication and characterization of sensors in LTCC (Low Temperature Co-fired Ceramics) technology;
• design, fabrication and characterization of CMOS integrated circuits (transceivers);
• data acquisition system.

1. Material Synthesis
The most important part of a sensor is the sensitive element which detects the change in value of the physical dimension in question. Such element represents the connection between the measured dimension and the electric signal forwarded to analog and digital units, which are also part of the sensor. Within SENSEIVER, the researchers synthesized and characterized new materials in order to evaluate their applicability in the production of new and innovative pollutant sensors. Planar impedancemetric NO sensors with thick film perovskite electrodes of different design were fabricated on yttria stabilized zirconia (YSZ) substrates. The investigation confirmed that the fabricated impedancemetric sensors can quantitatively differentiate NO concentration levels present in the gas mixture the sensor is exposed to. An equivalent circuit model of the sensor has been developed. All of the synthesized perovskite compounds seem to be suitable for sensing electrodes of NO, CO and oxygen sensors. Especially promising results were attained for neodymium, praseodymium and samarium based cobaltites.
2. Sensors
Low-temperature co-fired ceramic (LTCC) technology enables the integration of whole systems in one multilayer ceramic package, allowing integration of elements and components fabricated using different technologies, such as ICs, electrical interconnections and sensors. Technological work involved characterization of LTCC materials and development of lamination process using PMMA fugitive material for fabricating elements with cavities and microfluidic channels. A family of cost-effective LTCC sensors has been developed, such as: an inter-digitated capacitive sensor for detection of organic solvent-water mixtures and its read-out circuit, a water temperature sensor, a micro-fluidic sensor with incorporated cavity for liquid type and organic solvent-water mixtures recognition (using both exposed and buried contacts). A family of pH sensitive materials based on binary metal oxides have been developed during the project, and their integration into LTCC microsystems has been demonstrated. These ceramic pH sensors are characterized by low cost and easy fabrication, an they have excellent sensitivity in a wide pH range (2-12), fast response and long lifetime. Low-cost resistive sensors for various volatile organic compounds manufactured on organic substrates by in-situ polymerization have been also fabricated and tested.
3. Integrated circuit design
Concerning IR-UWB design, the common work on system requirements, specifications and top level system analysis has been initially performed, but shortly after it, two basic concepts have emerged. One, following the idea of commercially deployable technology based near to already available regulation and application standards, like IEEE 802.15.4a which are characterized by usage of pulse-based systems with limited spectral occupation and assigned frequency plan with using 528 MHz frequency channel spacing – internally defined as Impulse based Multi-band radio. And the other, based on generic concept of impulse based UWB radio, with inherently unlimited bandwidth, guided by USA FCC recommendation for short-range devices. During the course of the project, several fundamental blocks of IR-UWB systems were then developed following both routes, but with several common blocks, keeping the sense of a posterior integration: UWB low-noise amplifiers were designed and tested; an elliptical patch antenna on LTCC substrate was fabricated and tested; a wide linear input range OTA (sub-threshold), dynamic comparator and IFN (integrate and fire neuron) circuit; novel IR-IF (impulse radio – integrate and fire) UWB transmitter that promises strong gains in power efficiency. Simultaneously, passive mixers, low-pass filters with capacitor calibration, power detector, custom designed inductors and current references were also designed as integrant parts of the UWB systems.
4. Data acquisition
Developed sensors and readout electronics have been connected into a sensor network connecting several of project partners. The network uses ZigBee technology for short-range wireless communication while Internet is used for communication between partnering institutions, allowing read-time viewing of measurement results.

Within SENSEIVER, 16 ESRs and 4 ERs were employed. Twelve of the ESRs enrolled in PhD studies. Thirty-four secondments were successfully performed, lasting 54 months in total. Out of the mentioned 34 secondments, 12 of them were intersectoral, meaning that researchers working in academia performed 6 secondments at industrial partners and another 6 secondments were performed by researchers working in the industry sector visiting the partners of the academia sector.
The most important overall achievements of the SENSEIVER project are:
- 28 published papers in peer-reviewed journals, - 66 published papers at conferences
- 1 defended PhD thesis (ESR11), - 6 awards
- 15 info-days
- 20 meetings with stakeholders, - 10 management meetings
- 3 workshops, - 2 summer schools, - 1 final network conference
- 4 exhibitions (on technical fairs)
- 4 articles under review (submitted), - 2 follow-up H2020 proposals (submitted)
- 3 TV appearances, 3 radio interviews, - 3 articles in newspapers/magazines, - 2 promotional movies
- ESR11 was on a short list of 10 candidates for the “Promising Research Talent” award of MSCA Prizes 2014
- ESR1 was selected to be filmed as a success story for the Net4Mobility project financed by EC.