Instead of throwing used coffee in the trash or mixing it with non-consumables materials, we have developed a variety of water-based inks for 3D printers in different concentrations of spend coffee ground (SCG) which consist of consumables in favor of creating a biodegradable flower pot. SCG has a carbon-to-nitrogen ratio and is made from nutrients that can improve soil and plants. Also, coffee contains oils and caffeine that can suppress certain plant growth and even prevent the development of microorganisms that are harmful to plants. A 3D printer makes it possible to find a balance between the properties of coffee by a specific location of the concentration of coffee in space depending on the type of soil and the plant variety.
As proof of concept, over a two-week project, we showed feasibility by 3D printing SCG using a multi-material printer made with different coffee concentrations. Outwardly a high concentration of coffee is a protective layer for the plant that decomposes slowly and improves the soil, and inwardly a low concentration depending on the type of crop.
Out of dozens of candidates, Yinon and Doron's project was chosen for first place. More details about the competition can be found here
 The YouTube video is available with English subtitles: