Biological & Soft Matter Seminar: Design like an insect
Prof. Julian Vincent
Insects present some very good models for technical devices. Their outer covering - the cuticle - is a composite of chitin nanofibrils in a protein matrix. The ‘normal’ rules of a fibrous composite apply, but insects have taken this to the extremes. Modulus of the composite ranges over seven orders of magnitude at more or less constant density. Strains can be as large as 15 (i.e. 1,500% - if that has any meaning), high toughness, and hardness akin to metals and ceramics.
In one specific area - fracture mechanics applied to tunneling and boring - they have some lessons to teach that seem to be scaleable. For instance the design of the egg-laying ‘ovipositor’ of several species of woodwasp has been developed into a computer-controlled guided endoscope for examination and operations. The pathway from the insect to the surgical instrument was adventitious but can be generalised and objectified, resulting in reliable transfer of technology. With a proper understanding of the problems that organisms have solved, those solutions can be applied in surprising ways.