We, Mejdi and Vivien, optical and electronic engineers, are working together to develop OZIRMA. It is designed with cost and fablab-technologies in mind.
A lot of work has been done to decentralized and further plastic recycling (with initiatives such as PRECIOUS PLASTIC) but one essential piece of hardware is still missing: a reliable tool to identify the different types of plastics.
OZIRMA will be able to detect plastics from various types: PE, PP, PET, PS... and allows for better sorting at a lower cost.
Existing solutions are the expensive ones (50k to 100k€), used by large recycling facilities.
Smaller (portable) solutions exist, but still costs around 10k€.
The key ideas being our frugal design:
- Single pixel IR detector (InGaAs photodiode). Therefore, we need to scan (rotation) with a stepper-motor and the aquisition take some time...
- Infrared (NIR) LEDs: Lower power than a light bulb (~1mW vs 10W), but they put all their power in the right spectral bands.
- Moreover, the LEDs are modulated which increase the SNR (synchronous detection).
- Cheap transmission grating
- A crazy high-gain transimpedance amplifier: 1 GigaOhm (!!!) over 1kHz bandwith.
- Vertical scanning compensation of the focal (with a small linear motor), in order to allow for play and slight misalignment of the mechanics.
- Signal acquisition is done via a dedicated "main board", and signal processing is for handled by a host software.
Designed with open source in mind:
OZIRMA is an open-source-hardware project (will be when we'll have the time to finish it!) built solely with open-source softwares: GeoGebra, OpenSCAD, KiCAD, Python, and open-source firmware solutions (GCC / Modm).
We truly believe that open-source helps spreading and improving projects, and we want to share this tool to help reduce plastic waste !