TeraScan

The TeraScan project — “Terahertz Scanner for Plastic Circular Economy” — is a research and development initiative by Microwave Photonics GmbH, submitted under the EFRE/JTF NRW 2021–2027 programme. The project responds to a growing regulatory and environmental challenge: new EU and German legislation mandates significantly higher recycled material content in plastic packaging by 2030, rising to up to 95% by 2035. Current sorting technologies, particularly near-infrared (NIR) spectroscopy systems, are insufficient to reliably identify modern complex plastic packaging, including coloured, black, or metal-coated materials. Terahertz waves in the 220–330 GHz range have been shown in recent studies to outperform existing methods in plastic identification, as they can distinguish between different polymers based on their dielectric properties and penetrate a wide range of materials safely and without ionisation.

The central innovation of TeraScan is the development of what is, to the project team’s knowledge, the world’s first terahertz scanner for plastic identification in industrial recycling processes. Rather than illuminating materials at a single point — as existing THz systems do — TeraScan uses electronically steerable dielectric leaky-wave antennas (LWA) whose beam angle is controlled directly via the frequency of the emitted waves, enabling rapid line scanning across a moving conveyor belt. Frequency-tuneable THz oscillators based on optical heterodyne techniques, using wavelength-tuneable lasers and advanced THz photodiodes, generate the broadband THz signals required. AI-based algorithms handle both material identification and spatial localisation of plastic objects, with centimetre-level accuracy. Microwave Photonics GmbH brings extensive prior work to the project, including already developed WR3-band photodiode chips, first THz leaky-wave antenna designs, and AI algorithms for signal processing — all of which will be adapted and integrated into the scanner prototype over the two-year project duration.

Beyond the circular economy, TeraScan has broad transferability across multiple sectors. The underlying scanner concept can be adapted to other frequency ranges and materials, and the leaky-wave antenna approach is also applicable as a radar or imaging system — with potential applications in food inspection, pharmaceutical quality control, autonomous vehicles, airport security, and future 6G communications. All critical components, including photonic and electronic semiconductor chips, will be developed and manufactured in Germany or within the EU, contributing directly to European technological sovereignty.