In nature, biological materials and organisms are part of a circular process of production and degradation. This process sustains the Earth and living things on it. Humans, however, have introduced new materials and products which do not fit into the circular economy, resulting in waste, which—as we all know—is detrimental to the health of the planet. Research being conducted at the Singapore University of Technology and Design (SUTD) is aiming to create a process that allows for urban waste to be degraded and reused as a 3D printing material, thus creating a new type of circular economy.
The process being developed by the SUTD team is reportedly capable of allowing the “production and degradation of almost any object within a circular economy using additive manufacturing and urban waste.” The method was inspired by the principles of natural processes, which were applied to localized urban ecosystems.
In a preceding project, the researchers developed a fungus-like adhesive material, FLAM, made from chitin and cellulose derived from crustacean and insect shells, and wood and paper. Made from two of the most common organic polymers, FLAM was developed as an eco-friendly alternative to plastic that is biodegradable, flexible, durable and can be produced using 3D printing.
The challenge with the FLAM material was that it integrated chitin, which is typically harvested seasonally as a byproduct of the fishing industry, making it most available to rural coastal areas. To avoid having to transport the natural polymer—contributing negatively to its carbon footprint—the researchers set out to create a more localized solution, focused on using materials from within a regional ecosystem.
Interestingly, part of the solution was found in the black soldier fly (BSF)—an insect that is commonly used to break down organic materials like food waste into proteins, oils and other biomass. The fly’s shell, as the researchers found out, can also be used as a source of chitin.
Drawing from this, the researchers realized that chitin could be derived from many insects and natural organisms that can break down food waste, like worms and fungi. This means that there is the possibility to harvest chitin from whatever local insect or worm is used for bio conversion—a food breakdown technique that is becoming more popular.
The chitin can then be combined with locally sourced cellulose to create 3D printing materials, which can be turned into products and eventually be biodegraded with the help of insects, and so the cycle restarts.
“This new development will transform the way we manufacture, enabling an alternative model where materials are produced and consumed using locally available resources,” said Assistant Professor Javier G. Fernandez from SUTD, lead author of the study. “Also, it will allow anyone around the world to adapt and integrate general manufacturing to its surrounding ecosystem.”
SUTD Associate Professor Stylianos Dritsas, co-author of the paper, added: ”Close proximity and deep integration of production and consumption cycles inspired by biology within urban ecosystems may not only influence the way we inhabit the cities of tomorrow, but also upstream envision, design and build them.”