Projects

overview of research projects


Ballistic tongues

Ballistic tongues are specialized, rapidly launched tongues used by slow predators on land to capture distant prey. They are found in three vertebrates: chameleons, lungless salamanders and frogs. They are fast, typically moving at mean speeds of 1–3 m/s and reaching prey within about 200 milliseconds.

My research focuses on:

  • biomechanical principles underlying the efficiency and versatility of ballistic tongues
  • evolution of ballistic tongues
  • ballistic tongue-inspired technology
The latest finding features a shared biomechanical architecture for ballistic launch in chameleons and salamanders (Zeng et al., 2025).
Ballistic tongues in salamanders and chameleons.

Insect flight

• Flight evolution

Winged insects are the first flight-capable animals evolved on land. To decipher the origin of winged insects and evolution of insect flight, I examined the biomechanics and evolutionary transitions between wingless and winged forms.

Using the stick insects (Phasmatodea) as a model system, I study:

  • evolution of flight-related morphology
  • the transition in flight capability (powered flapping flight, gliding and parachuting)
  • the transition in wing aerodynamics
The stick insects exhibit a continuous spectrum in wing size and wing aerodynamics (Zeng et al., 2020; Zeng et al., 2023).
A male stick insect (Diardia signata) from Borneo.

• Aerial Righting

Aerial righting is the first stage of a series of controlled behaviors in a falling insect. My research use stick insects as a model to show how aerial righting is done in small arthropods (Zeng et al., 2017; Ortega-Jimenez et al., 2023; Jusufi et al., 2011).
Aerial righting behavior.

• Gliding

Many wingless arthropods (e.g. ants, stick insects, and spiders) can perform steep glides after falling from height. I study why and how they glide, and how gliding may mediate the transition between parachuting and powered flapping flight (Zeng et al., 2015; Zhao et al., 2023; Zeng et al., 2020).
Gliding in stick insects.

Shape-shifting appendages

The flat spiders can strike prey from any direction. These maneuvers are performed with high angular speed thanks to highly coordinated leg movements (Zeng & Crews, 2018).
Omnidirectional strike in flat spiders.

Tadpole Biomechanics

Coming soon
Feeding and locomotion in frog tadpoles.

Hagfish thread

Hagfish can eject a highly dilute yet strong slime to defend against predators. This slime contains threads that rival spider silk in strength. My work examines the evolutionary origin and development of these thread cells (Zeng et al., 2021; Zeng et al., 2023).
Hagfish slime and gland thread cell.

Flagellated carpooling

Most microorganisms either swim or drift. My research reveals a new mode based on collective rolling behavior, in which the mobile and immobile cells aggregate and move together as rolling colonies (Zeng & Liu, 2020).
Caulobacter colonies forming motile structures.

Funding sources


2025

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    Convergently evolved linear actuators in ballistic tongues
    Yu Zeng ,  Christopher V Anderson ,  and  Stephen M Deban
    Current Biology, 2025

2023

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    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 and biomimetics, 2023
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    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
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    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

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    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

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    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
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    Self-propelling and rolling of a sessile-motile aggregate of the bacterium Caulobacter crescentus
    Yu Zeng ,  and  Bin Liu
    Communications Biology, 2020

2018

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    Biomechanics of omnidirectional strikes in flat spiders
    Yu Zeng ,  and  Sarah Crews
    Journal of Experimental Biology, 2018

2017

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    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 Responses: A Comparative Approach
    A Jusufi ,  Y Zeng ,  RJ Full ,  and  R Dudley
    In INTEGRATIVE AND COMPARATIVE BIOLOGY , 2011