About

Sheila N Patek is a Professor of Biology at Duke University, holding her position since 2019 within the Trinity College of Arts & Sciences. Her primary research focus is to examine the dynamic interplay between evolutionary processes and the mechanics of organisms. Her laboratory investigates how biological systems move and function at extremely fast speeds, often exploring the biomechanics of small systems and impulsive biological movements. Her work includes studying the biomechanics of predatory behaviors in animals such as cuttlefish, with recent publications detailing high-speed imaging of tentacle prey capture and biphasic tentacle strike kinematics. Professor Patek has contributed to understanding the evolution and mechanics of rapid movements in biological systems through her research projects, which include collaborative studies funded by the National Science Foundation and the Army Research Office. Her research aims to guide scalable synthetic design by understanding the biomechanics of muscles, springs, impacts, and deformations in nature, robotics, and materials. She is recognized for her contributions to experimental biology and biomechanics, and her work has been featured in various news outlets and scientific publications.

Research topics

• Artificial Intelligence
• Computer Science
• Physics
• Engineering
• Classical mechanics
• Mechanics
• Simulation
• Structural engineering
• Geometry
• Mathematics
• Biology
• Biological system
• Optics
• Environmental science
• Mechanical engineering

Selected publications

• Fourier light field imaging for ultra-high speed measurement of exoskeleton deformations in snapping trap-jaw ants

  2025-03-19

  article

  In this work, we present the Ultra-High Speed Fourier Light Field Mesoscope (US-FLFM) to measure 3D exoskeleton deformations in snapping trap-jaw ants. This system uses concepts from Fourier Light Field Imaging alongside an ultra-high speed imaging sensor (the Photron E980S, which can achieve 1 MHz+ frame rates) and a custom image processing pipeline to capture tiny (um) and brief (us) movements occurring over a mm scale ant head. This system provides new insight into Latch Mediated Spring Actuation (LaMSA), the mechanism behind some of the most extreme energetic events known to science, which allows a wide range of organisms to snap, jump, spear, and launch projectiles with remarkably high acceleration and energy output.

  PublisherDOI

• JEB launches a new article type for theory and modelling studies

  Journal of Experimental Biology · 2024-12-12

  articleOpen access1st authorCorresponding

  JEB recently launched a new article type called Theory & Modelling. With this new article type, we address the need across the fields of comparative physiology and biomechanics to publish research that leverages modelling and theory to address new biological questions.JEB has published works of theory for decades (e.g. Gray and Hancock, 1955; Weis-Fogh, 1973; Sane, 2006) and many of these contributions have been highly influential. However, articles primarily focused on theory and modelling are difficult to fit within the guidelines of our Research Article and Short Communication article types, which require collection of substantial new experimental datasets. Novel theoretical frameworks often require significant development which can be challenging to present in conjunction with significant experimental datasets. Therefore, Theory & Modelling articles do not require substantial new biological datasets and permit a more flexible arrangement of section headings compared with our other paper categories. To encourage further exploration of the ideas and approaches in these papers, this article type also requires digital deposition of the datasets and non-proprietary code in forms that are readily usable by other researchers. Overall, our goal is to provide readers with new insights into the application of modelling to experimental data and exemplify how modelling can guide testable hypotheses and predictions for future research. Aligning with JEB's focus on experimental biology, we encourage authors to propose experimental approaches for future studies to test the new ideas emerging from their theory and modelling study.Five Theory & Modelling papers were published during the first year of this new article type. Two of these papers apply theory and modelling approaches to muscle contractions. Labonte and Holt (2024) introduce a dimensionless quantity called the physiological similarity index. They define this index as the ratio of kinetic energy capacity to work capacity to explain muscle performance limits across scales. Their study suggests that muscle performance is limited not by power output but instead by a characteristic kinetic energy capacity. Their modelling approaches facilitate comparisons of muscle performance in movements across size scales. Van der Zee et al. (2024) tackle the cascade of processes preceding a muscle contraction, examining the cellular and subcellular basis for rate limits in muscle contractions. Their study identifies rate-limiting processes in muscle contractions which can be tested in future experiments.Three new Theory & Modelling papers examine the principles of movement in soft-bodied animals, force transfer in bones and aerodynamics of flying snakes. Ellers et al. (2024) model the tube feet of sea stars and the soft-bodied movements of earthworms. By establishing the principles of force and displacement advantage in hydrostatic systems, their findings encourage targeted experimental data collection to rigorously test the mechanics of locomotion in soft-bodied systems. Wilken et al. (2024) use load path analysis to map force transfer in the mandible of the Virginia opossum and evaluate the impact of trabecular and cortical bone configurations. Their study highlights the utility of load path analysis for exploring skeletal form–function relationships. Finally, Yeaton et al. (2024) incorporate empirical datasets with predictive quasi-steady models to examine the aerodynamics of snake flight. They find that quasi-steady approaches underpredict snake flight performance, which indicates that snakes likely rely on unsteady aerodynamic forces for their remarkable flight capabilities. These findings encourage future experimental research to test and identify unsteady mechanisms of aerodynamic force generation in flying snakes.We hope that authors across the fields of comparative physiology and biomechanics will submit their outstanding theory and modelling studies through this new article type. For more information about publishing in this category, please see the guide to authors: https://journals.biologists.com/jeb/pages/article-types#theory.

  PublisherOA PDFDOI

• Mantis Shrimp Locomotion: Coordination and Variation of Hybrid Metachronal Swimming

  Integrative Organismal Biology · 2023-01-01 · 9 citations

  articleOpen accessSenior author

  Synopsis Across countless marine invertebrates, coordination of closely spaced swimming appendages is key to producing diverse locomotory behaviors. Using a widespread mechanism termed hybrid metachronal propulsion, mantis shrimp swim by moving five paddle-like pleopods along their abdomen in a posterior to anterior sequence during the power stroke and a near-synchronous motion during the recovery stroke. Despite the ubiquity of this mechanism, it is not clear how hybrid metachronal swimmers coordinate and modify individual appendage movements to achieve a range of swimming capabilities. Using high-speed imaging, we measured pleopod kinematics of mantis shrimp (Neogonodactylus bredini), while they performed two swimming behaviors: burst swimming and taking off from the substrate. By tracking each of the five pleopods, we tested how stroke kinematics vary across swimming speeds and the two swimming behaviors. We found that mantis shrimp achieve faster swimming speeds through a combination of higher beat frequencies, smaller stroke durations, and partially via larger stroke angles. The five pleopods exhibit non-uniform kinematics that contribute to the coordination and forward propulsion of the whole system. Micro-hook structures (retinacula) connect each of the five pleopod pairs and differ in their attachment across pleopods—possibly contributing to passive kinematic control. We compare our findings in N. bredini to previous studies to identify commonalities across hybrid metachronal swimmers at high Reynolds numbers and centimeter scales. Through our large experimental dataset and by tracking each pleopod's movements, our study reveals key parameters by which mantis shrimp adjust and control their swimming, yielding diverse locomotor abilities.

  PublisherOA PDFDOI

• Geometric latches enable tuning of ultrafast, spring-propelled movements

  Journal of Experimental Biology · 2023-01-06 · 15 citations

  articleOpen accessSenior author

  The smallest, fastest, repeated-use movements are propelled by power-dense elastic mechanisms, yet the key to their energetic control may be found in the latch-like mechanisms that mediate transformation from elastic potential energy to kinetic energy. Here, we tested how geometric latches enable consistent or variable outputs in ultrafast, spring-propelled systems. We constructed a reduced-order mathematical model of a spring-propelled system that uses a torque reversal (over-center) geometric latch. The model was parameterized to match the scales and mechanisms of ultrafast systems, specifically snapping shrimp. We simulated geometric and energetic configurations that enabled or reduced variation of strike durations and dactyl rotations given variation of stored elastic energy and latch mediation. Then, we collected an experimental dataset of the energy storage mechanism and ultrafast snaps of live snapping shrimp (Alpheus heterochaelis) and compared our simulations with their configuration. We discovered that snapping shrimp deform the propodus exoskeleton prior to the strike, which may contribute to elastic energy storage. Regardless of the amount of variation in spring loading duration, strike durations were far less variable than spring loading durations. When we simulated this species' morphological configuration in our mathematical model, we found that the low variability of strike duration is consistent with their torque reversal geometry. Even so, our simulations indicate that torque reversal systems can achieve either variable or invariant outputs through small adjustments to geometry. Our combined experiments and mathematical simulations reveal the capacity of geometric latches to enable, reduce or enhance variation of ultrafast movements in biological and synthetic systems.

  PublisherOA PDFDOI

• A century of comparative biomechanics: emerging and historical perspectives on an interdisciplinary field

  Journal of Experimental Biology · 2023-04-22 · 1 citations

  articleOpen access1st authorCorresponding

  This Special Issue showcases JEB's central role in historical, current and future comparative biomechanics research. Comparative biomechanics is defined as the scientific study of the mechanics of non-human organisms, including animals, plants and fungi. Mechanics is the branch of physics that addresses the forces and displacements that relate to movement. Comparative biomechanics research is traditionally conducted at the tissue and whole-organism levels, including the mechanical interactions between whole organisms and the environment. JEB's scope is primarily restricted to scientific research on animal systems, yet has included key papers about plants and fungi when the findings have broad relevance to animals. While being an integral part of the newer fields of biophysics (cellular to molecular levels of physics analysis), mechanobiology (transduction of forces at molecular to tissue levels) and bioinspiration/biomimetics (synthetic design based on biological systems), comparative biomechanics enriches ecological and evolutionary biology by integrating mechanics, morphology and the environment through studies across diverse species.The papers in this Special Issue focus on broad biological questions addressed through the lens of comparative biomechanics. Cross-cutting through time, this Special Issue addresses questions from the vantage points of the history of the field, today's research and the future of comparative biomechanics. Leveraging JEB's range of paper categories, these topics are explored through Commentaries, Reviews and Research Articles. The assembled authors represent diverse contributions – from early career researchers (see associated ECR Spotlight interviews) to senior members of the field. The Special Issue builds from the foundational definition of comparative biomechanics (force and displacement; mechanics) to explore influences of comparative biomechanics on other fields, such as environment/ecology, evolution and engineering.Biomechanics, by definition, requires measurements and analyses of force and movement. The historical foundation of kinematic measurements and extraordinary advances in the amount and quality of these measurements are captured in McHenry and Hedrick's (2023) Review of imaging technology used across the past century of biomechanics articles. Their analyses of the published literature reveal the correlates of major shifts in imaging technology that have enabled larger datasets and a greater number of sampled individuals. Demuth et al. (2023) review the remarkable technological advances in 3D reconstruction of morphology and movement, while offering an integrated workflow for researchers wishing to integrate 3D approaches into their studies of organismal movements. Provini et al. (2023) provide a Commentary on the promise and pitfalls of using high-resolution 3D motion data to address questions about complex movement dynamics, and Manafzadeh (2023) offers a Commentary focused on joint mobility with insights arising directly from the major recent strides in 3D imaging and reconstruction.Focusing on the interface of technology and analyses of animal biomechanics, three papers tackle topics within particular systems – bird bills, cheetah locomotion and hummingbird feeding. Krishnan's (2023) Review of the diverse morphologies, materials, mechanics and sensory capabilities of bird bills exemplifies the powerful discovery space arising from the integration of new technologies – from imaging to materials testing – across one widespread yet diverse animal structure. In Shield et al.’s (2023) Review, the extraordinary capabilities of cheetahs are considered from the lens of technology. By reviewing the historical research about cheetah biomechanics and muscle physiology – many of the discoveries driven by technology – the authors offer insights into sensors and methodologies that apply broadly to other biomechanical systems. The Research Article by Rico-Guevara et al. (2023) uses state-of-the-art high-speed videography and backlighting to understand the active role that hummingbird bills play in helping their tongues transport nectar intraorally, from tongue to throat, shedding light on nectarivory in hummingbirds with extremely diverse bill morphologies.Technology and biomechanics have also thrived through their alliance with engineering. Harvey et al. (2023) probe the deeply historical and currently burgeoning interface between biomechanics and engineering, specifically from the perspective of flying systems in natural environments. Their Review not only highlights specific areas of translation – related to bird wings – but also offers a synthesis of the deep history of these synergies even beyond the past century and extending to the inventions of Leonardo da Vinci. The engineering–biomechanics connection continues to be an engine of discovery and the rich, data-driven experimental work over JEB's history offers invaluable insights for quantitatively driven engineering translation.Encapsulating the crucial interconnections of biomechanics and naturally variable environments, Koehl (2023) begins her Review with a quote from Vogel and Wainwright's lab manual ‘Structure without function is a corpse, and function without structure is a ghost’, and follows with her own twist: ‘and an organism without its environment is a mirage’. Koehl's Review examines classic biomechanics topics – from locomotion to biomaterials – and for each example, she highlights the shift in understanding when the role of the environment is included, such as animals carrying cargo or materials adjusting to environmental loads. Clifton et al. (2023) probe a similar theme from a pragmatic position – how can researchers systematically yet broadly study animal walking on naturally variable substrates? Taking these themes to the air, Combes et al. (2023), in a Research Article, focus on measuring insect flight in natural environmental conditions. Their study exemplifies how new technology enables massive datasets from which subtle but crucial adjustments by animals in the natural environments are quantitatively addressed.The integration between biomechanical systems, technological developments and environment–system interactions is exemplified in Nirody (2023) and Jimenez et al.’s (2023) Reviews. Nirody explores exciting new developments emerging from system–environment interactions in a neural framework through studies of panarthropod locomotion. Her Review not only encourages neural–biomechanical integration but also encourages broader taxonomic exploration in biomechanical studies to incorporate deeply historic animals, such as water bears (tardigrades). While Nirody's Review encourages exploration of new systems, Jimenez et al.’s Review encourages revisiting a classic system – fish swimming – via analysis of emergent biomechanical properties of fish bodies in fluids. Like Nirody, Jimenez et al. note the importance of a broad taxonomic incorporation of diverse fishes alongside the use of new technologies to understand system–environmental interactions.Muscle dynamics is a historical foundation of biomechanics and has been a major focus over JEB's history. Mendoza et al. (2023) review the principles of muscle contractions in the context of diverse animal muscle physiology. The authors connect the historical foundations of force–length and force–velocity relationships to newer discoveries in non-model systems and comparative studies. Their Review encourages engagement of veteran muscle physiologists looking toward new and exciting systems and early career researchers interested in tying together core principles of muscle mechanics. James et al.’s (2023) Review integrates these foundational principles of muscle (and tendon) physiology into the realm of anthropogenic impacts, including endocrine disruptors and climate change. They offer examples of evolved abilities ranging from narrow temperature windows of consistent ability to generate muscle-driven motion, to remarkable toleration of highly variable environments and physiological conditions (such as dehydration). Flash and Zullo (2023) examine muscle physiology and dynamic modeling in the context of muscular hydrostats – mechanisms of long-standing interest to biomechanists given the remarkable capabilities and unusual muscle physiology that enables controlled movements in soft systems. Focusing within this topic of muscular hydrostats, Thompson et al.’s (2023) Research Article examines obliquely striated muscle in squid tentacles that informs a broader understanding of the multiple evolutionary origins of these remarkable muscles.We hope that readers will explore all the papers in this Special Issue – many not mentioned in this brief, introductory cover article. We hope that this Centenary Special Issue serves as an influential and enduring reflection on the historical and present-day impact of the field of comparative biomechanics. This collection will hopefully inform wide-ranging communities: early career researchers learning about major historical works and today's relevance, mid-career and senior researchers seeking to enhance their teaching and their own technical skills/perspectives, and funders/scientific administrators who can be provided with these Commentaries, Reviews and Research Articles that exemplify the importance of comparative biomechanics today and into the next century.

  PublisherOA PDFDOI

• Author response: Tradeoffs explain scaling, sex differences, and seasonal oscillations in the remarkable weapons of snapping shrimp (Alpheus spp.)

  2023-02-24

  peer-reviewOpen accessSenior author

  From deer antlers to crab claws, weapons are some of the most elaborate and enormous structures in the animal kingdom. Within a species, weapon size generally increases with the size and condition of an individual, and those with larger weapons are usually better at fending off more diminutive competitors. Although it may seem desirable for all individuals to have large weapons, size varies greatly within a species. The ‘handicap principle’ proposes that the cost of bearing a weapon dictates the variation in weapon size. Smaller or less fit individuals pay more for weapons than larger or fitter animals, so smaller individuals tend to grow smaller weapons. Although popular, only a handful of studies have demonstrated experimental evidence that supports this theory. To test the handicap principle, Dinh and Patek studied a group of crustaceans known as snapping shrimp. Each shrimp has one enlarged claw that it uses as a weapon to fire imploding vapor bubbles at opponents during fights. Larger snapping shrimp have bigger enlarged claws and tend to win more contests. Males also have larger weapons than females, and this sex difference is amplified during the breeding season. Dinh and Patek studied weapon size in several species of snapping shrimp. Measurements showed that after controlling for body size, individuals with larger weapons had smaller abdomens, suggesting there is a tradeoff between weapon size and abdomen size. Furthermore, small males exhibited the steepest tradeoff, in line with the handicap principle. Snapping shrimp also showed sex-specific costs and benefits. After controlling for body size, females with larger weapons produced fewer and smaller eggs, while males with larger weapons were more likely to be paired with females and generally paired with larger females. This suggests that weapons are particularly burdensome to female shrimp and particularly beneficial to males, especially during the breeding season. These findings provide elusive evidence for the handicap principle and extend the theory to explain sex and seasonal differences in the size of snapping shrimp weapons. More broadly, the findings highlight the value of studying both male and female animal weapons when, historically, the focus has been on male weaponry.

  PublisherDOI

• Developing elastic mechanisms: ultrafast motion and cavitation emerge at the millimeter scale in juvenile snapping shrimp

  Journal of Experimental Biology · 2023-02-15 · 8 citations

  articleOpen accessSenior author

  Organisms such as jumping froghopper insects and punching mantis shrimp use spring-based propulsion to achieve fast motion. Studies of elastic mechanisms have primarily focused on fully developed and functional mechanisms in adult organisms. However, the ontogeny and development of these mechanisms can provide important insights into the lower size limits of spring-based propulsion, the ecological or behavioral relevance of ultrafast movement, and the scaling of ultrafast movement. Here, we examined the development of the spring-latch mechanism in the bigclaw snapping shrimp, Alpheus heterochaelis (Alpheidae). Adult snapping shrimp use an enlarged claw to produce high-speed strikes that generate cavitation bubbles. However, until now, it was unclear when the elastic mechanism emerges during development and whether juvenile snapping shrimp can generate cavitation at this size. We reared A. heterochaelis from eggs, through their larval and postlarval stages. Starting 1 month after hatching, the snapping shrimp snapping claw gradually developed a spring-actuated mechanism and began snapping. We used high-speed videography (300,000 frames s-1) to measure juvenile snaps. We discovered that juvenile snapping shrimp generate the highest recorded accelerations (5.8×105±3.3×105 m s-2) for repeated-use, underwater motion and are capable of producing cavitation at the millimeter scale. The angular velocity of snaps did not change as juveniles grew; however, juvenile snapping shrimp with larger claws produced faster linear speeds and generated larger, longer-lasting cavitation bubbles. These findings establish the development of the elastic mechanism and cavitation in snapping shrimp and provide insights into early life-history transitions in spring-actuated mechanisms.

  PublisherOA PDFDOI

• Elastic pinch biomechanisms can yield consistent launch speeds regardless of projectile mass

  Journal of The Royal Society Interface · 2023-08-01 · 4 citations

  articleOpen accessSenior author

  Energetic trade-offs are particularly pertinent to bio-ballistic systems which impart energy to projectiles exclusively during launch. We investigated such trade-offs in the spring-propelled seeds of Loropetalum chinense , Hamamelis virginiana and Fortunearia sinensis . Using similar seed-shooting mechanisms, fruits of these confamilial plants (Hamamelidaceae) span an order of magnitude in spring and seed mass. We expected that as seed mass increases, launch speed decreases. Instead, launch speed was relatively constant regardless of seed mass. We tested if fruits shoot larger seeds by storing more elastic potential energy (PE). Spring mass and PE increased as seed mass increased (in order of increasing seed mass: L. chinense , H. virginiana , F. sinensis ). As seed mass to spring mass ratio increased (ratios: H. virginiana = 0.50, F. sinensis = 0.65, L. chinense = 0.84), mass-specific PE storage increased. The conversion efficiency of PE to seed kinetic energy (KE) decreased with increasing fruit mass. Therefore, similar launch speeds across scales occurred because (i) larger fruits stored more PE and (ii) smaller fruits had higher mass-specific PE storage and improved PE to KE conversion. By examining integrated spring and projectile mechanics in our focal species, we revealed diverse, energetic scaling strategies relevant to spring-propelled systems navigating energetic trade-offs.

  PublisherOA PDFDOI

• Tradeoffs explain scaling, sex differences, and seasonal oscillations in the remarkable weapons of snapping shrimp (Alpheus spp.)

  eLife · 2023-04-21 · 4 citations

  articleOpen accessSenior author

  Evolutionary theory suggests that individuals should express costly traits at a magnitude that optimizes the trait bearer's cost-benefit difference. Trait expression varies across a species because costs and benefits vary among individuals. For example, if large individuals pay lower costs than small individuals, then larger individuals should reach optimal cost-benefit differences at greater trait magnitudes. Using the cavitation-shooting weapons found in the big claws of male and female snapping shrimp, we test whether size- and sex-dependent expenditures explain scaling and sex differences in weapon size. We found that males and females from three snapping shrimp species (Alpheus heterochaelis, Alpheus angulosus, and Alpheus estuariensis) show patterns consistent with tradeoffs between weapon and abdomen size. For male A. heterochaelis, the species for which we had the greatest statistical power, smaller individuals showed steeper tradeoffs. Our extensive dataset in A. heterochaelis also included data about pairing, breeding season, and egg clutch size. Therefore, we could test for reproductive tradeoffs and benefits in this species. Female A. heterochaelis exhibited tradeoffs between weapon size and egg count, average egg volume, and total egg mass volume. For average egg volume, smaller females exhibited steeper tradeoffs. Furthermore, in males but not females, large weapons were positively correlated with the probability of being paired and the relative size of their pair mates. In conclusion, we identified size-dependent tradeoffs that could underlie reliable scaling of costly traits. Furthermore, weapons are especially beneficial to males and burdensome to females, which could explain why males have larger weapons than females.

  PublisherDOI

• Through the looking glass: attempting to predict future opportunities and challenges in experimental biology

  Journal of Experimental Biology · 2023-12-07 · 7 citations

  articleOpen access

  To celebrate its centenary year, Journal of Experimental Biology (JEB) commissioned a collection of articles examining the past, present and future of experimental biology. This Commentary closes the collection by considering the important research opportunities and challenges that await us in the future. We expect that researchers will harness the power of technological advances, such as '-omics' and gene editing, to probe resistance and resilience to environmental change as well as other organismal responses. The capacity to handle large data sets will allow high-resolution data to be collected for individual animals and to understand population, species and community responses. The availability of large data sets will also place greater emphasis on approaches such as modeling and simulations. Finally, the increasing sophistication of biologgers will allow more comprehensive data to be collected for individual animals in the wild. Collectively, these approaches will provide an unprecedented understanding of 'how animals work' as well as keys to safeguarding animals at a time when anthropogenic activities are degrading the natural environment.

  PublisherOA PDFDOI

Recent grants

• CAREER: The evolutionary mechanics of rapid movement

  NSF · $707k · 2013–2019

• Comparative Mechanics of Rapid Predatory Movements

  NSF · $106k · 2009–2010

• Collaborative Research: Moving with muscles vs. springs: evolutionary biomechanics of extremely fast, small systems

  NSF · $784k · 2020–2026

• CAREER: The evolutionary mechanics of rapid movement

  NSF · $536k · 2012–2014

Frequent coauthors

• Jonathon H. Stillman

  San Francisco State University

  49 shared

• Marvalee H. Wake

  University of California, Berkeley

  49 shared

• Dianna K. Padilla

  Stony Brook University

  49 shared

• Mark W. Denny

  49 shared

• Brian Tsukimura

  California State University, Fresno

  49 shared

• Thomas Claverie

  Ifremer

  17 shared

• S. M. Cox

  Duke University

  16 shared

• Mark Ilton

  Robert Bosch (Germany)

  15 shared

Education

• Postdoctoral Fellow, Miller Institute for Basic Research in Science

  University of California, Berkeley

  2004

• Ph.D., Biology

  Duke University

  2001

• A.B.

  Harvard University

  1994