Have you ever wondered where Velcro came from, or how a Kindle screen can be read in the sunlight? A quick internet search reveals that both of these technologies were human ideas inspired by fundamental properties of nature. Ever since our ancestors had gained the ability to think in a complex manner, humans have continually studied the other multicellular organisms that surround them. Early on, the goal of this research may have just been to determine where to hunt for prey, but the human-animal relationship has evolved over time to one in which our society can now appreciate the animal kingdom’s finer details and the amazing adaptations that species have made in response to their environments. One thing that our species has learned for sure, though, is that we have only scratched the surface of the vast knowledge we can gain from animals.
Recently, I had the opportunity to speak with Tufts University Professor Barry Trimmer, the Henry Bromfield Pearson Professor of Natural Sciences and the Director of the Neuromechanics and Biomimetic Devices Laboratory, about his research. His work has emerged from the lessons of the animal kingdom and focuses on how we can best adapt such knowledge to benefit our society. Professor Trimmer’s research encompasses three distinct, but interconnected, categories: the neuromechanics of movement, softworm robots, and tissue engineering. However, all three of these categories originate from the study of a simple, often overlooked creature – the worm.
Professor Trimmer, who started his career with a sole focus on biology, was originally investigating how nerve cells pass information to signal movement. His research “snowballed” and led him to one of the field’s biggest puzzles, known as the degrees of freedom problem. Take the human elbow, for example: the bone and joint structure allow the elbow to move in a single, defined motion. However, if you were to remove the bones, it would have unlimited degrees of freedom, and flop around aimlessly. While scientists have determined much of the biomechanics that allow vertebrates to control movement, none have determined how soft-body creatures, such as jellyfish, octopuses, and worms, can also move precisely without a hard material to react with and limit the organism’s movement.
Early research centered around first mimicking the flexibility of these creatures by utilizing many small rigid components that link together to create a larger robot. However, these early systems lacked the same dexterity and were difficult to control. Professor Trimmer realized that the answer was actually right in front of him. Instead of trying to modify key aspects of an organismal process, why not just replicate all of its key features? This directed his research not only at soft-body robots, but also at the complex neurological problems of how to control them. He identified the tobacco hornworm, scientifically known as Manduca sexta, as the optimal model system because it had solved the complicated degrees of freedom problem with a brain consisting of only a few neurons. Today, Professor Trimmer is working to use silicone and other polymers to form shapes that replicate the plasticity of the worm and other similar animals. In order to control these newly developed structures, small wires and electrodes are implanted that can send electrical impulses which then react with the material of these robots to create movement.