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Abstract Ultrafast movements propelled by springs and released by latches are thought limited to energetic adjustments prior to movement, and seemingly cannot adjust once movement begins. Even so, across the tree of life, ultrafast organisms navigate dynamic environments and generate a range of movements, suggesting unrecognized capabilities for control. We develop a framework of control pathways leveraging the non-linear dynamics of spring-propelled, latch-released systems. We analytically model spring dynamics and develop reduced-parameter models of latch dynamics to quantify how they can be tuned internally or through changing external environments. Using Lagrangian mechanics, we test feedforward and feedback control implementation via spring and latch dynamics. We establish through empirically-informed modeling that ultrafast movement can be controllably varied during latch release and spring propulsion. A deeper understanding of the interconnection between multiple control pathways, and the tunability of each control pathway, in ultrafast biomechanical systems presented here has the potential to expand the capabilities of synthetic ultra-fast systems and provides a new framework to understand the behaviors of fast organisms subject to perturbations and environmental non-idealities.
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Exquisite energetics of spring-propelled, latch-mediated movements
Ultrafast organisms exemplify how biological systems manipulate and control energy to generate spectacularly diverse movements. Across the tree of life, repeateduse, ultrafastmovements are driven by springs and controlled by opposing, latch-like forces. We focus on the biomechanical processes that sequentially reduce the duration of each energetic event to yield intense mechanical power density - often external to the organism to reduce self-damage.We leverage a new model system of young, transparent mantis shrimp (Stomatopoda) to quantify the timing and dynamics of muscle contraction, storage of elastic potential energy, latch engagement and release, and the levers and linkages that transform elastic potential to kinetic energy of their ultrafast strikes. We examine how the convergence of physical limits and inherent evolutionary integration of biomechanical structures yield generalizable features of energy storage and energy delivery, such that these mechanisms occur exclusively in small systems.While ultrafast organisms have historically been invisibly fast to science, today’s technology and new model systems have unveiled effective experimental approaches to quantifying energetic control and manipulation in these intriguing biomechanical systems.
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- Award ID(s):
- 2019355
- PAR ID:
- 10469360
- Publisher / Repository:
- Society for Integrative and Comparative Biology
- Date Published:
- Volume:
- 63
- Issue:
- s1
- Page Range / eLocation ID:
- S350
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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