Projects

a quick overview of research projects


Biomechanics and evolution of insect flight

- Where did flight and wings come from ?

Winged insects are the first flight-capable animals evolved on land. To decipher the principles underlying the complex architecture of insect flight, I examined the biomechanics and evolutionary transitions between wingless and fully-winged forms. Specifically, I study the transition between flapping and non-flapping wings and the transition between powered flapping flight, gliding and parachuting. The stick insects (Phasmatodea) with a diversity of wing morphologies is my model system.

A male stick insect (Diardia signata) from Borneo, as captured by high-speed camera.

keywords wings, flapping, elasticity, inertia, legs, forest canopy, powered flight, gliding

(Zeng et al., 2020; Zeng et al., 2023)


Aerial Righting & Gliding

- controlled aerial behaviors with wings or legs

keywords legs / forest canopy / stability / control

Many wingless arboreal animals can glide and perform agile aerial maneuvers. To understand the aerodynamic utilities of non-wing appendages and its relationship with the evolution of wings, I study various non-flight aerial behaviors, such as righting, falling and gliding. These study systems include a diversity of arthropods that glide and fly, such as stick insects, ants and, most recently, orchid mantises with petal-shaped legs.

Aerial righting and gliding in nympha stick insects (Extatosoma tiaratum).

(Zeng et al., 2017; Zeng et al., 2015; Ortega-Jimenez et al., 2023; Zhao et al., 2023; Zeng et al., 2020; Jusufi et al., 2011)

An orchid mantis nymph glides after being released.

(Zhao et al., 2023)


Shape-shifting appendages

Rapid maneuvers mediated by shape-shifting appendages and body.

Omnidirectional strike in flat spiders.

(Zeng & Crews, 2018)


Tadpole Biomechanics

- coming soon

Feeding and locomotion in frog tadpoles.


Ballistic Appendages

- Rapid projection and retraction

Chameleons and many lungless salamanders can quickly project their tongues to capture distant prey. In both animals, tongues function as ballistic appendage for rapid reach-and-retrieval. Both ballistic tongue systems feature a tubular accelerator muscle coupled with tapered skeletal elements and slender, elongated retractor muscles. I study the biomechanical principles underlying the efficiency and versatility of these intriguing designs.

keywords predator-prey / rapid movement / precision control

Ballistic tongues in salamanders and chameleons. Videos by Stephen Deban and Christopher V. Anderson.

Hagfish thread

- Packaging of the longest intra-cellular fiber

Hagfish can eject a highly dilute yet strong slime to defend against predators. This slime contains threads that rival spider silk in strength and are the longest known intracellular fibers. My research addresses the developmental mechanism and evolutionary origin of this intriguing bio-material.

(Zeng et al., 2021; Zeng et al., 2023)

Hagfish slime and gland thread cell (GTC).

keywords biofiber / predator-prey / intracellular / morphogenesis


Flagellated carpooling

- a noval bacterial locomotion

Most microorganisms are known to either swim by a flagellum or passively disperse with flow. My research reveals a new mode built on division-of-labor in the bacterium Caulobacter crescentus, where immotile cells and flagellated cells aggregate and roll like wheels.

Sessile and motile Caulobacter cells aggregate and form motile colonies.

(Zeng & Liu, 2020)

keywords microorgnaism / colonial transport / fluid dynamics


Acknowledgements


2023

  1. et-wing_smallcrop.jpg
    Beyond winglets: evolutionary scaling of flight-related morphology in stick insects (Phasmatodea)
    Yu Zeng ,  Sehoon Park ,  Camille Gonzales ,  Stephanie Yom ,  Faszly Rahim ,  and  Robert Dudley
    Biological Journal of the Linnean Society, 2023
  2. Air-to-land transitions: from wingless animals and plant seeds to shuttlecocks and bio-inspired robots
    Victor M Ortega-Jimenez ,  Ardian Jusufi ,  Christian E Brown ,  Yu Zeng ,  Sunny Kumar ,  Robert Siddall ,  Baekgyeom Kim ,  Elio J Challita ,  Zoe Pavlik ,  Meredith Priess ,  and  others
    Bioinspiration & biomimetics, 2023
  3. mantis-small.png
    Petal-shaped femoral lobes facilitate gliding in orchid mantises
    Xin Zhao ,  Jing-Xin Liu ,  Tristan Charles-Dominique ,  Ahimsa Campos-Arceiz ,  Bing Dong ,  Lin Yan ,  James C O’Hanlon ,  Yu Zeng ,  and  Zhanqi Chen
    Current Biology, 2023
  4. etc-small.png
    Epidermal threads reveal the origin of hagfish slime
    Yu Zeng ,  David C Plachetzki ,  Kristen Nieders ,  Hannah Campbell ,  Marissa Cartee ,  M Sabrina Pankey ,  Kennedy Guillen ,  and  Douglas Fudge
    Elife, 2023

2021

  1. GTC_stack_small.gif
    Evolution of a remarkable intracellular polymer and extreme cell allometry in hagfishes
    Yu Zeng ,  Skylar Petrichko ,  Kristen Nieders ,  David Plachetzki ,  and  Douglas Fudge
    Current Biology, 2021

2020

  1. winglets_1.png
    A tale of winglets: evolution of flight morphology in stick insects
    Yu Zeng ,  Connor O’Malley ,  Sonal Singhal ,  Faszly Rahim ,  Sehoon Park ,  Xin Chen ,  and  Robert Dudley
    Frontiers in Ecology and Evolution, 2020
  2. et.roll.1.gif
    Canopy parkour: movement ecology of post-hatch dispersal in a gliding nymphal stick insect, Extatosoma tiaratum
    Yu Zeng ,  Sofia W Chang ,  Janelle Y Williams ,  Lynn Y-Nhi Nguyen ,  Jia Tang ,  Grisanu Naing ,  Chandni Kazi ,  and  Robert Dudley
    Journal of Experimental Biology, 2020
  3. rosette_tiny2.gif
    Self-propelling and rolling of a sessile-motile aggregate of the bacterium Caulobacter crescentus
    Yu Zeng ,  and  Bin Liu
    Communications Biology, 2020

2018

  1. movie_s1_original-size-1.gif
    Biomechanics of omnidirectional strikes in flat spiders
    Yu Zeng ,  and  Sarah Crews
    Journal of Experimental Biology, 2018

2017

  1. right_tracrop.gif
    Biomechanics of aerial righting in wingless nymphal stick insects
    Yu Zeng ,  Kenrick Lam ,  Yuexiang Chen ,  Mengsha Gong ,  Zheyuan Xu ,  and  Robert Dudley
    Interface Focus, 2017

2015

  1. Visual ecology of directed aerial descent in first-instar nymphs of the stick insect Extatosoma tiaratum
    Yu Zeng ,  Yvonne Lin ,  Arianna Abundo ,  and  Robert Dudley
    The Journal of Experimental Biology, 2015

2011

  1. Aerial righting reflexes in flightless animals
    Ardian Jusufi ,  Yu Zeng ,  Robert J Full ,  and  Robert Dudley
    2011