Animal Attachment
Then: "Sticking" to the Basics
Now: Mastering Micro-Adhesion
Geckos have adhesive toe pads on the underside of their feet which help them attach to surfaces.
You might not know it, but many of the adhesives we use in our everyday lives draw inspiration from animals. As technology advances, scientists' ability to use biology to create better adhesives also improves. Austin Garner, an assistant professor of biology, investigates the biomechanics of animal movement and attachment, aiming to understand how factors such as climate change impact animals' mobility within their environments. Additionally, Garner explores how animal attachment can be applied to human engineering to develop better smart materials. Hear from Garner on how the field of bio-inspired adhesion has changed and what advancements are in store for the future.
How has research on animal attachment and bio-inspired adhesion evolved over the past 25 years?
Austin Garner (AG): The turn of the century was accompanied by a flood of studies focusing on animal and bio-inspired attachment, likely because of advances in technology that allowed us to better probe the physical and chemical mechanisms driving attachment.
How have recent technological advances in imaging and force sensing impacted our understanding and application of bio-inspired attachment mechanisms in various animal systems?
AG: Advances in both imaging and force sensing have allowed us to not only observe attachment phenomena at smaller and smaller scales, but have also permitted measurement of the actual, and sometimes tiny, forces involved in attachment processes.
Concurrently, we have witnessed improvements in our abilities to manufacture complex and smart materials that have enhanced our ability to incorporate bio-inspired design principles into human-made attachment devices. These advances have directly increased the diversity of animal systems we are now capable of exploring.
Animals of focus have ranged dramatically in body size, from small insects like ants and beetles to animals over several inches in length like geckos, fishes and octopuses to even large mammals like polar bears, as well as the environment in which they live—terrestrial and aquatic animals alike have received considerable research attention.
What are your predictions for the future of this field over the next quarter-century?
AG: In many animal systems, we now have a basic understanding of the major principles driving attachment in relatively controlled laboratory conditions. But “controlled” is the last word I would use to describe the environments that animals live in. Over the next quarter-century, I expect both life and physical scientists to dive deeper into how animals manage to produce robust attachment in the variable, and sometimes unpredictable, conditions that are characteristic of the habitats that they live in.
What challenges and opportunities exist in expanding the study of attachment mechanisms across a broader range of animal species, both in the lab and in the field?
AG: We have only begun to scratch the surface of the diversity of animals that use attachment in their natural habitats. For example, there are currently ~2,389 species of gecko currently recognized, and we have probably only studied attachment in a very small number of these, likely much less than 100.
Additionally, even fewer species have been used as models for implementation into bio-inspired attachment devices. Thus, there is a lot to learn about animal and bio-inspired attachment if we begin to expand the number of species we study these topics in. I predict (and hope!) that this will be the case over the next 25 years.
Are there bio-inspired attachment design principles that are currently being applied in the real world, or is this something we can expect to see more of by 2050?
AG: Absolutely! There’s a popular bio-inspired attachment system probably in most of our houses at this very moment: Velcro®. Velcro® was actually inspired by the mechanism that burr plants use to attach their dried seeds—very well, I might add—to the fur of mammals to increase their dispersal. Burr seeds are covered in tiny hooks that interlock with animal fur to generate firm attachment. Velcro® uses this same principle for the strong, yet reversible, attachment that many of us make use of regularly.
There are a number of other bio-inspired adhesives that have made their way to the market (e.g., based on gecko toe pads), but none are really commonplace. Many of these adhesives are still quite expensive, likely related to the high cost and difficulty in manufacturing them. I predict that we will see more bio-inspired adhesives on the market between now and 2050, especially if our manufacturing technology continues to advance at its current rate.
