Scientists develop eco-friendly 3D printed polymer parts from terrestrial insects

An international team, including researchers from India, has successfully developed a method of using a compound from terrestrial insects to manufacture eco-friendly polymer composite parts with the 3D printing method.

The researchers, including those from Sri Ramakrishna Engineering College in Tamil Nadu, used Chitosan derived from chitin, a compound found in the exoskeletons of arthropods such as insects, as well as in sea creatures such as the shells of crabs.

The 3D printing technology is a form of manufacturing which has become popular in recent times due to its ability to produce complex shapes and geometries difficult to achieve using traditional manufacturing techniques.

As a result, the demand for raw material for 3D printing is on the rise. It is crucial to ensure responsible usage of raw materials for 3D printing to meet the UN Sustainable Development Goal 12, i.e., promoting sustainable consumption and production patterns.

Terrestrial insects are a potential source of chitosan due to their abundance, accessibility, and relatively high chitin content in their exoskeletons.

There are several potential benefits to extracting chitosan from terrestrial insects, including sustainable and eco-friendly production.

Insects are a sustainable source of chitosan, as they can be easily farmed and harvested in large quantities without contributing to environmental pollution.

In contrast, traditional sources of chitosan such as shrimp and crab shells can be unsustainable and have negative environmental impacts.

The study, published in the Journal of Polymers and the Environment, investigated the feasibility of developing an environmentally friendly composite material using 3D printing technology,

The team, including resaerchers from Saveetha Institute of Medical and Technical Sciences, Tamilnadu, found that the addition of chitin and chitosan, derived from terrestrial insects, to the polylactic acid (PLA) matrix led to a decrease in strength and stiffness, which worsened with increasing concentrations of chitin and chitosan. PLA is the most widely used plastic filament material in 3D printing.

The composite material with 0.5 per cent by weight chitin reinforcement had the lowest tensile and flexural strength compared to other composites produced using additive manufacturing, the researchers said.

The reduction in strength and stiffness of the chitin/PLA and chitosan/PLA composites, in comparison to neat PLA, was attributed to the decreased interfacial bonding between the reinforcement and matrix, they said.

The chitin/PLA and chitosan/PLA composites demonstrated enhanced ductility relative to neat PLA, with the 0.1 weight per cent chitin composite showing the highest ductility, the degree to which a material can sustain stress.

The study concluded that chitin and chitosan could contribute to toughening the PLA composite.

The team also found that the density of the composites increased with increasing concentrations of chitin and chitosan.

The Chitin/PLA and Chitosan/PLA composites exhibited good thermal stability, and could have potential applications for food product packaging based on their compressive properties, the researchers added.

Other researchers in the study are from Singapore Institute of Technology, Newcastle University in Singapore, Mahidol University in Thailand, and Universiti Teknologi Malaysia.