A biological approach to metalworking based on chitinous colloids and composites

TL;DR

This paper introduces a novel, eco-friendly metalworking method using chitosan-based colloids that produces high-metal-content composites at ambient conditions, enabling functional shapes and biological integration.

Contribution

It presents a new biological approach to metalworking utilizing chitosan colloids, contrasting with traditional high-energy methods, and demonstrates functional, printable, and biologically compatible metal composites.

Findings

Composites contain over 99.5% metal with metallic properties.

Manufacturing occurs at ambient temperature and pressure.

Composites can be printed, cast, and infused into biomaterials.

Abstract

Biological systems evolve with minimum metabolic costs and use common components, and they represent guideposts toward a paradigm of manufacturing that is centered on minimum energy, local resources, and ecological integration. Here, a new method of metalworking that uses chitosan from the arthropod cuticle to aggregate colloidal suspensions of different metals into solid ultra-low-binder-content composites is demonstrated. These composites, which can contain more than 99.5% metal, simultaneously show bonding affinity for biological components and metallic characteristics, such as electrical conductivity. This approach stands in contrast with existing metalworking methods, taking place at ambient temperature and pressure, and being driven by water exchange. Furthermore, all the nonmetallic components involved are metabolized in large amounts in every ecosystem. Under these conditions, the composites' ability to be printed and cast into functional shapes with metallic characteristics is demonstrated. The affinity of chitometallic composites for other biological components also allows them to infuse metallic characteristics into other biomaterials. The findings and robust manufacturing examples go well beyond basic demonstrations and offer a generalizable new approach to metalworking. The potential for a paradigm shift toward biomaterials based on their unique characteristics and the principles of their manufacturing methods is highlighted.