Currently only ~32% of Europe’s plastic waste is recycled, with the rest either being “thermally recycled” (= being burnt) or going to landfill. To achieve a circular economy, the fraction that is recycled must be massively increased. Current sorting systems are not able to differentiate between i) food vs. non-food grade plastics, or ii) bioplastics vs. traditional fossil-fuel based plastics; as well as iii) other difficult to recycle polymers.
The goal of this project is to build a bench scale version of a plastic sorting machine that simulates rubbish moving on a conveyor belt at ~3 m/s. As well as engineering the moving parts, the system will need to shine light on the “rubbish” (pieces of plastic), detect the luminescence signal, and decode what polymer this is.
A particular challenge is how many unique “codes” can be generated given the number of materials that luminesce at different wavelengths. This can be imagined like a RGB colour code, where mixing a certain amount of the red-emitting phosphor with the green and blue ones yields a unique colour. The challenge is to be able to repeatably and reliably detect this colour code as it moves at high speed.
The “Nanophotonics for Energy” division was established at KIT 2014 within the Institute of Microstructure Technology (IMT) and the Light Technology Institute (LTI). On the systems level, we are working on development of various sustainable technologies, including photovoltaics, solar-powered water treatment systems, as well as luminescent materials for anti-counterfeiting and plastic recycling.
Figure. A wide range of luminescent materials can be mixed into polymers to provide a unique signal that assists with improving plastic recycling. Here examples in the visible as shown, but we also utilize materials that emit in the near-infrared wavelength range.
Contract's duration: 6 Months
Entry date: on appointment
Personal qualifications:
The student should have a strong interest in realizing a circular economy and a sustainable future. Together with a German industry partner, we are developing a technology based around adding luminescent materials to plastics that are currently difficult and/or impossible to recycle. This project is at the systems engineering level, meaning that experience in both mechanical and electrical engineering is ideal, along with some exposure to optics. To complete the ambitious project within the limited time requires hard work, self-motivation, and cooperation with other colleagues in a multidisciplinary and international research group (N4E).
