The seat rests on a tubular steel skeleton – intended to last for hundreds of years – and is made from a mixture of leaves and bio-resin made from leftover cooking oil. The material is pressed into a mould and, once set, sanded and attached to the framework.
"I wanted to use a strong structure to work as a 'trunk and branches for leaves'," Kern told Dezeen. "There is also a lot of curves in the frame, so I decided that tubular steel had the best mechanical features for my purpose."
The designer also hopes that the seat can be easily replaced if it gets worn out or broken.
"If it gets damaged we just put it under the tree, where it disappears into the soil and fertilises a tree," he said. "Then we pick the fallen leaves once again, and make a new seat."
Kern is still perfecting the process, designing more ergonomic and biodegradable versions of the seat. He also plans to experiment with using the leaf material for lighting.
Brands are also experimenting with the possibilities of recycled material, with IKEA incorporating plastic bottles into kitchen units and US company Loll Designs using discarded milk packaging for a collection of outdoor furniture.