Smart systems for environmental pollution detection and biogas production based on cloud-connected silicon photonic and microelectronic hyperspectral sensors

Project Information

SYMPHONY

Grant agreement ID: 101135523

DOI

10.3030/101135523

EC signature date 28 November 2023

Start date 1 April 2024

End date 30 September 2027

Funded under

• Digital, Industry and Space

Total cost

€ 4 982 272,00

EU contribution

€ 4 982 272,00

Coordinated by

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
France

Periodic Reporting for period 1 - SYMPHONY (Smart systems for environmental pollution detection and biogas production based on cloud-connected silicon photonic and microelectronic hyperspectral sensors)

Reporting period: 2024-04-01 to 2026-03-31

Summary of the context and overall objectives of the project

Air pollution remains one of the most significant environmental threats to human health, causing nearly half a million premature deaths annually across Europe. Expanding access to ubiquitous, real-time air quality (AQ) monitoring could substantially mitigate the impact of pollution. However, current monitoring systems largely depend on complex, stationary, and expensive equipment, typically costing several thousand euros, which limits their large-scale deployment.

At the same time, tackling climate change is a critical priority. Biogas production has been recognized as a key enabling technology for achieving the European Union’s 2030 greenhouse gas (GHG) emission reduction targets and offers strong potential to support Europe’s transition to net-zero emissions by 2050. Furthermore, biogas represents an important component of Europe’s energy diversification strategy, helping to reduce dependence on external energy sources. Nevertheless, biogas plant operators and manufacturers require significant advances in sensing technologies to improve process optimization, system control, and leak detection. Similar sensing solutions could also provide valuable monitoring capabilities for greenhouse gases in the global oil and gas (O&G) sector.

SYMPHONY addresses these challenges by developing an innovative sensing platform that combines multiple silicon photonics technologies with advanced silicon microelectronics. The project aims to enable dense networks of cloud-connected, low-cost (below €100), portable (5–80 cm³), and user-friendly smart sensors capable of simultaneous multi-gas detection for air quality monitoring and biogas production, paving the way for large-scale deployment in a variety of applications.

To achieve this vision, SYMPHONY will advance the state of the art in silicon photonics, neuromorphic circuits, artificial intelligence (AI), system integration, and packaging. These innovations will be combined with cutting-edge silicon microelectronics for ultra-low-power edge AI processing and interconnected sensor networks capable of spatially resolved monitoring, analysis, and predictive modelling.

The project focuses on the detection of: (i) gases identified by the European Environment Agency (EEA) as both major pollutants and contributors to climate change, including methane (CH₄, with a CO2-equivalent impact of 28–36) and nitrous oxide (N2O, with a CO2-equivalent impact of 265–298); and (ii) gases essential for biogas production processes, namely CH₄, CO2, and H2S. In addition, the exceptionally broad hyperspectral operating range of the SYMPHONY sensors will enable monitoring of other important gases relevant to agriculture, such as NH₃, and to the food and beverage industry, including H2S and NO2.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

M1–M18
The primary milestone for this reporting period was the definition of application scenarios (MS1), linked to deliverable D2.1 which has been successfully completed. System-level and component-level specifications were subsequently established (D2.2). The fabrication of the Gen1 photonic circuits at ST CROLLES was initiated in M8, slightly delayed from the originally planned M6 (see GA Part B §1.2.2). This first-generation design already integrates advanced circuits for Fourier-transform processing and neuromorphic AI functionalities operating in the near-infrared domain. Work has also begun on the development of key building blocks targeting the mid-infrared range (D4.1). In parallel, initial deep-learning models have been developed using pre-existing experimental datasets, with compatibility for deployment on ST CROLLES edge-computing infrastructure.

Dissemination and outreach activities have been actively pursued, including presentations of SYMPHONY results at multiple conferences, three journal publications involving project outcomes, and additional outreach events such as a high-school presentation and IEEE seminars. Diversity and inclusion considerations have also been addressed, notably through a gender awareness seminar organised by CNRS during the kick-off meeting. A structured collaboration framework has been implemented across partners, including regular consortium-wide meetings and the creation of focused sub-groups dedicated to specific technical tasks.

M19–M24
The fabrication of the Gen1 photonic platform at ST CROLLES has been successfully completed, and the resulting devices have been characterised. Key building blocks, including Fourier-transform spectrometer components and neuromorphic AI circuits, have been evaluated, leading to the identification of optimisation points that are currently being addressed in preparation for the Gen2 fabrication run scheduled for the second half of 2026.
Dissemination and awareness activities have continued as planned, including leadership of the European Cluster of Research projects for Environmental and Agri-food Monitoring (ECREAM).
Regrettably, Dr. Reiner Goetzen became seriously ill in November 2025 (M20) and passed away on 04 February 2026 (M23). Following the subsequent closure of microTEC-D on 01 February 2026 (M23), the consortium has developed a mitigation plan to redistribute the remaining tasks of microTEC-D among project beneficiaries, complemented by limited subcontracting of non-research activities. A project extension request is included as part of this plan, and an amendment will be submitted at the earliest opportunity in RP2.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

SYMPHONY will establish a unique position in the low-cost gas sensing market by delivering simultaneous advances in hardware, software, and system architecture. The project will leverage the intrinsic advantages of optical gas sensors—namely high selectivity, high sensitivity, low drift, and minimal maintenance requirements—while pushing beyond the current state of the art in three key areas:

Spectral coverage – Hyperspectral sensing across both the near-infrared (NIR) and mid-infrared (MIR) spectral regions.

Gas identification – Automated on-board analyte recognition enabled by advanced deep-learning algorithms.

Data intelligence – Wireless transmission of sensor data to cloud-based platforms for large-scale analytics and advanced AI-driven inference.

The most significant innovation of SYMPHONY is the introduction of hyperspectral capabilities into the low-cost optical gas sensor market, representing a major technological breakthrough. Existing optical gas sensors are typically restricted to the detection of a single gas species because their performance relies on complex optical assemblies that dominate manufacturing costs. By replacing these assemblies with a fully integrated photonic solution, SYMPHONY combines the robustness and maturity of non-dispersive infrared (NDIR) sensing with state-of-the-art silicon photonics technology. This approach removes a substantial portion of assembly-related costs while enabling compact, scalable, and multi-gas sensing functionality that is not achievable with current low-cost optical sensor platforms.