Animals like cheetahs are well known for their extreme speed. Still, their ability to accelerate quickly is orders of magnitude slower than that of creatures, including fleas, froghoppers, mantis shrimps, trap-jaw ants, and click beetles—which are capable of achieving stunningly high accelerations, particularly when hunting or escaping predators. What these all have in common is that their fast movements are not powered directly by muscles. Instead, they use a system of springs and latches.
Current literature already describes this extreme locomotion at the small scale, including earlier work from MechSE Assistant Professor Aimy Wissa. So far, however, it’s limited to kinematics (i.e., position, velocity, and acceleration) or morphology characterization.
With a new CAREER grant (Faculty Early Career Development Program) from the National Science Foundation, Wissa aims to build on a gap in those earlier studies by focusing on measuring and modeling the dynamics, or the forces that enable the springs and latches to cause these ultrafast movements.
In her proposal, she is using click beetles as a case study organism to develop the experimental methods and numerical models required to understand the dynamics of high acceleration movements at the small scale. Wissa has been studying click beetles for a handful of years now, through multiple interdisciplinary collaborations.
“In this research, I’m asking ‘How can these insects make this really fast maneuver over and over again, without damage. How do they route the energy through their small, volume-constrained bodies?” Wissa said. “More specifically, I am interested in discovering the internal spring system in click beetles and in studying how the distribution of these internal springs affects the energy routes within the body? And is there a specific way to organize the springs to maximize acceleration but also mitigate damage?’
With her five-year funded project, “Dynamics of Extreme Locomotion in Biological and Bioinspired Systems: The Effect of Distributed Elasticity on Mobility and Mechanical Power Flow,” she will build an analytical framework to help answer the energy-routing question, then use that framework to design a microscale robot.
“The microrobots developed so far by several researchers, compared to these insects in nature, are much slower, and even if they are very fast, they tend to be damage-prone. The design process is also ad hoc – designed mainly based on trial and error – and It’s hard to take principles designed for a specific robot and truly apply them to another microrobot. That’s why I want to create a model-based design framework so that we can all understand how to design better microrobots,” Wissa said.
Additionally, much of Wissa’s work on this project will feed directly into her bioinspired design course (ME 498/IB 496), which is open to biologists and engineers and offered next fall.
Wissa is also planning two related outreach activities in collaboration with the campus’s Office of Minority Student Affairs (OMSA). For OMSA’s Talent Search – a weekend program supporting middle- and high-school students from Champaign, Urbana, Danville, and Decatur – Wissa will work with MechSE Education Outreach Coordinator Joe Muskin to develop an activity in which the students design jumpers that rely on springs to locomote. Another of OMSA’s programs, Upward Bound, is a six-week summer college-prep program helping students improve their math and science skills. For this, Wissa created an outreach track that exposes the students to engineering, acceleration, dynamics, and more, showing them what it’s like to be an engineer. ENVISION, an organization spearheaded by MechSE graduate students, will help Wissa and OMSA run the program and allow participants to see student researchers in action. This effort will help incorporate an engineering component into Upward Bound.
Wissa earned her PhD in aerospace engineering from the University of Maryland in 2014 and joined MechSE in 2015. She runs the Bio-inspired Adaptive Morphology Laboratory (BAM Lab) at UIUC.