1
|
Hyun NP, Olberding JP, De A, Divi S, Liang X, Thomas E, St Pierre R, Steinhardt E, Jorge J, Longo SJ, Cox S, Mendoza E, Sutton GP, Azizi E, Crosby AJ, Bergbreiter S, Wood RJ, Patek SN. Spring and latch dynamics can act as control pathways in ultrafast systems. Bioinspir Biomim 2023; 18:026002. [PMID: 36595244 DOI: 10.1088/1748-3190/acaa7c] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 12/09/2022] [Indexed: 06/17/2023]
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.
Collapse
Affiliation(s)
- N P Hyun
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, United States of America
| | - J P Olberding
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA 92697, United States of America
| | - A De
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, United States of America
| | - S Divi
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States of America
| | - X Liang
- Polymer Science and Engineering Department, University of Massachusetts Amherst, Amherst, MA 01003, United States of America
| | - E Thomas
- Polymer Science and Engineering Department, University of Massachusetts Amherst, Amherst, MA 01003, United States of America
| | - R St Pierre
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States of America
| | - E Steinhardt
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, United States of America
| | - J Jorge
- Biology Department, Duke University, Durham, NC 27708, United States of America
| | - S J Longo
- Biology Department, Duke University, Durham, NC 27708, United States of America
| | - S Cox
- Biology Department, Duke University, Durham, NC 27708, United States of America
| | - E Mendoza
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA 92697, United States of America
| | - G P Sutton
- School of Life Sciences, University of Lincoln, Lincoln, United Kingdom
| | - E Azizi
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, CA 92697, United States of America
| | - A J Crosby
- Polymer Science and Engineering Department, University of Massachusetts Amherst, Amherst, MA 01003, United States of America
| | - S Bergbreiter
- Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA 15213, United States of America
| | - R J Wood
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, United States of America
| | - S N Patek
- Biology Department, Duke University, Durham, NC 27708, United States of America
| |
Collapse
|
2
|
Abstract
The snap of a finger has been used as a form of communication and music for millennia across human cultures. However, a systematic analysis of the dynamics of this rapid motion has not yet been performed. Using high-speed imaging and force sensors, we analyse the dynamics of the finger snap. We discover that the finger snap achieves peak angular accelerations of 1.6 × 106° s-2 in 7 ms, making it one of the fastest recorded angular accelerations the human body produces (exceeding professional baseball pitches). Our analysis reveals the central role of skin friction in mediating the snap dynamics by acting as a latch to control the resulting high velocities and accelerations. We evaluate the role of this frictional latch experimentally, by covering the thumb and middle finger with different materials to produce different friction coefficients and varying compressibility. In doing so, we reveal that the compressible, frictional latch of the finger pads likely operates in a regime optimally tuned for both friction and compression. We also develop a soft, compressible friction-based latch-mediated spring actuated model to further elucidate the key role of friction and how it interacts with a compressible latch. Our mathematical model reveals that friction plays a dual role in the finger snap, both aiding in force loading and energy storage while hindering energy release. Our work reveals how friction between surfaces can be harnessed as a tunable latch system and provides design insight towards the frictional complexity in many robotic and ultra-fast energy-release structures.
Collapse
Affiliation(s)
- Raghav Acharya
- Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30311, USA
| | - Elio J. Challita
- Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30311, USA,George W. Woodruff School of Mechanical Engineering, Georgia Tech, Atlanta, GA 30311, USA
| | - Mark Ilton
- Department of Physics, Harvey Mudd College, Claremont, CA 91711, USA
| | - M. Saad Bhamla
- Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30311, USA
| |
Collapse
|