Additive manufacturing with biobased materials as a step toward a circular economy

Exploring technology readiness and opportunities for urban applications

Humanity faces serious environmental challenges as an effect of climate change. Increased rates of pollution, rising sea levels, and resource depletion are threatening all living organisms through degradation of vital ecosystems, biodiversity loss, and species extinction (Gil Lamata & Latorre Martínez, 2022). In the past, Earth’s resources seemed infinitely available and therefore less discretion was used in the consumption of those resources. Centuries of irresponsible over-consumption put pressure on today’s society to mitigate the critical trajectory of our planet’s future. The European Union as well as some national governments and businesses recognize the transition to a circular economy as a promising strategy for addressing the ongoing climate crisis (Korhonen et al., 2018).

A circular economy (CE) is the ideology that waste must be eliminated – all outputs of one system must become inputs for the next. It is an economic model designed to promote resource efficiency, reduce waste, and create economic, social, and environmental benefits. Unlike the traditional linear economy, which involves extracting resources, using them to make products, and disposing of them after use, a circular economy seeks to keep resources in use for as long as possible through strategies such as repair, reuse, and recycling (Neves & Marques, 2022). One proposed strategy for achieving sustainable resource use is the shift toward products and materials that can be derived from renewable and biological origins. This has led to a rising interest in biobased, biodegradable, compostable, and recycled materials (Javaid et al., 2021). Heightened awareness of the pollutive and destructive effects of fossil-dependent industries has led to ever more initiatives to find sustainable alternatives. Biobased materials are increasingly being considered as a replacement for some conventional – often less sustainable – materials across many industries and taking various forms (Faludi et al., 2019).

Sustainable alternatives are introduced not only at the product level through novel material use but also in the product design and manufacturing processes through digitization and computerization (Ruby & Ruby, 2020; Setaki & van Timmeren, 2022). Additive manufacturing (AM) – or 3D printing – is a manufacturing technique that has been growing in popularity. The fundamental elements of AM are an object built layer-by-layer by means of a digitally modeled design. The digital model is ‘sliced’ into many layers, enabling the robotic 3D printer to construct the model with precision and speed.

Additive manufacturing is considered a disruptive technology as it facilitates the creation of complex structures and on-demand production (Garmulewicz et al., 2018; Setaki & van Timmeren, 2022). Companies no longer have to preproduce or store spare parts. Instead, they can just print them when needed. Rapid availability of spare parts leads to an extension of the service life of devices and other products. AM is also beginning to disrupt the construction industry through both 3D-printed building components and complete structures and houses. AM reduces the time, cost, and labor required to build homes (Rael & San Fratello, 2018). In addition, it is considered environmentally friendly, as it helps limit cumulative waste produced during construction. Moreover, material flexibility in AM is sparking immense interest and experimentation in the quest for more sustainable material options. The manufacture of products with novel, biobased, and biocompostable materials is on the horizon (Faludi et al., 2019).

Certain AM methods can accept a broad range of input materials. However, plastics account for a vast majority of materials used in AM today, which are regarded as unsustainable and directly harmful to our planet. The collective push to reduce consumption of fossil-based plastic is gaining momentum, underpinning the demands for suitable (sustainable) alternatives. Herein lies the opportunity for biobased material development from renewable sources. The balance between available resources and their use for growth and development should be maintained. Prioritizing the use of biobased, biodegradable, and compostable materials presents optimistic ways of addressing the growing concerns of resource overconsumption, waste production, and pollution. This is especially relevant in the urban context, where offenders such as the construction industry are among the most pollutive (Ruby & Ruby, 2020; Setaki & van Timmeren, 2022). Numerous projects already include the use of 3D printing in design and construction, such as furniture and consumer goods, as well as building components and full-scale residential structures (Rael & San Fratello, 2018).