Microscopy of Biological Materials for Bioinspired Design

Nature provides many solutions to challenges faced by organisms. Well-known examples include the way a gecko can cling to smooth surfaces and the water-harvesting forewings of the Namib desert beetle. Bioinspiration is the understanding of systems in nature and how we can modify and replicate these for human design and engineering. Classic biomimicry of natural shapes has focused on the surface or overall structures. X-ray microscopy (XRM) and microtomography (µCT) have the potential to reveal hidden internal microarchitectures, as well as the ability to generate 3D representations of complex surface structures. Using X-ray µCT/XRM, we’ve investigated a number of species including cuttlefish (Sepia officinalis), woodlice (Armadillidium vulgare), and barnacles (Semibalanus balanoides). Imaging has revealed complex internal architectures that are only visible using nondestructive methods. Understanding the organism’s behavior is essential when considering the functions of these complex forms, requiring first-hand observation or collaboration with species specialists. The overall architecture of cuttlebone, unique to cuttlefish, provides function by regulating buoyancy, and ultimately depth in the sea, but the finer internal CaCO3 structure revealed by µCT is even more enigmatic. Woodlice use their articulating armor plates for defense. µCT imaging showed how these structures interact and move, with a combination of soft and hard tissue. We also visualized in 3D the interlocking plates secreted to encase barnacles. Rapid prototyping was used to gain greater insight into these structures and to consider their bioinspiration potential. 3D imaging reveals a new dimension, opening up a myriad of structures, forms, and functions in nature to be discovered, studied, and adapted for engineering applications.

In addition, correlative imaging between lengthscales is a powerful tool for investigating hierarchical and multi-scale materials. At AIM, we’ve developed the capability to correlate across X-ray imaging, scanning and light microscopy, chemical/microstructural analyses, and mechanical properties in one integrated facility.

Key Learnings:

• Learn how XRM can triage organisms and structures of interest and identify next steps in characterization workflows.
• Understand how XRM and connected/correlative imaging and characterization can provide insight to biology, as well as feeding into bioinspired design.