As research into synthetic biology matures, so do the potential applications, with scientists ensuring new discoveries are put to credible use. We highlight recent biomimetic material innovations – from shrimp-inspired metal alternatives to antibacterial contact lenses modelled after insect wings.
- Mantis Metal: A team of researchers from Purdue University in Indiana and the University of California are developing a new metal-like composite inspired by the mantis shrimp, a crustacean found in the Indian and Pacific oceans. Its claws are impact-resistant – a property being reinterpreted in a bid to design an advanced, metal-like material for use in body armour and auto parts.
The claw follows a helicoidal structure, with the fibres positioned in a spiral arrangement, which allows it to endure repeated strikes without damage. It’s the first time this structure has been found in nature, and forms the basis of the new material’s composition.
For more on ocean-inspired materials, see Shrimp Bioplastic.
- Sea-Sponge Concrete: Researchers at the Massachusetts Institute of Technology are looking to deep-sea sponges and nacre (the inner shell layer found in molluscs) to develop a new sustainable cement paste – the main ingredient in concrete. Cement paste is made with OPC (ordinary Portland cement) – the manufacture of which is responsible for almost 5% of man-made CO2 emissions.
The deep-sea sponge has a layered silica structure that prevents it from cracking. Nacre has a similar layered structure with strong mineral bonds that makes it highly durable. By combining the mechanical properties of these different organisms, the team hopes to revolutionise the cement industry by creating an eco-friendly version with an added level of defence against surface damage.
For more on concrete innovations, see Fabric-Cast Concrete, Cork & Concrete Composite and Recasting Concrete.
- Ultra-Resilient Spider Silk: Scientists from the Pierre and Marie Curie University in Paris are collaborating with SABIP (Silks as Biomimetic Ideals for Polymers), an EU-funded material innovation project. They are hoping to create a new liquid/solid hybrid material inspired by spider webs for use in smart textiles and new synthetic wire.
The team discovered that spider silk is coated with an absorbent glue substance that swells and forms into droplets. The durable droplets allow the thread to coil and unravel repeatedly without losing its original shape or strength, making it strong and stretchy.
Understanding this unique behaviour has led to the development of a synthetic silk that mimics the same properties using a nylon thread and sugar solution. The synthetic silk is produced at relatively low temperatures without any harsh chemicals and is easily recyclable. They are currently exploring ideas for novel uses and ways to upscale it.
See also Honed Synthetics, Artificial Bee Silk, Insects in Design and Spider-Silk Implants.
- Bacteria-Fighting Plastic: Chemical engineers at the University of California in Irvine have developed a new antibacterial plastic inspired by the wings of the cicada family of insects. The plastic mimics the common surface and texture of their wings, which have thousands of sharp pillars that can kill bacteria. The flexibility and sterilising quality of the new material makes it ideal for contact lenses.
Using the versatile plastic PMM (polymethylmethcrylate) as a base, the team moulded nanopillars like those found on cicada wings into the material. During testing, the plastic material was able to kill thin-walled bacteria like E. coli immediately upon contact, but a new formula is in development to target bacteria with thicker cell walls.
For more on biomimetic material innovations, see Biomimicry in Design, Hybrid S/S 17 Update: Future Manufacturing, and Direct from Nature.