PreprintPDF Available

The Natural Robotics Contest: Crowdsourced Biomimetic Design

Preprints and early-stage research may not have been peer reviewed yet.

Abstract and Figures

Biomimetic and Bioinspired design is not only a potent resource for roboticists looking to develop robust engineering systems or understand the natural world. It is also a uniquely accessible entry point into science and technology. Every person on Earth constantly interacts with nature, and most people have an intuitive sense of animal and plant behavior, even without realizing it. The Natural Robotics Contest is novel piece of science communication that takes advantage of this intuition, and creates an opportunity for anyone with an interest in nature or robotics to submit their idea and have it turned into a real engineering system. In this paper we will discuss the competition's submissions, which show how the public thinks of nature as well as the problems people see as most pressing for engineers to solve. We will then show our design process from the winning submitted concept sketch through to functioning robot, to offer a case study in biomimetic robot design. The winning design is a robotic fish which uses gill structures to filter out microplastics. This was fabricated into an open source robot with a novel 3D printed gill design. By presenting the competition and the winning entry we hope to foster further interest in nature-inspired design, and increase the interplay between nature and engineering in the minds of readers.
Content may be subject to copyright.
The Natural Robotics Contest: Crowdsourced
Biomimetic Design
Robert Siddall1*, Raphael Zufferey2, Sophie Armanini3,
Ketao Zhang4, Sina Sareh5and Elisavetha Sergeev1
1University of Surrey, Guildford, UK.
Ecole polytechnique ed´erale de Lausanne (EPFL), Lausanne, Switzerland.
3Technische Universit¨at unchen, Munich Germany.
4Queen Mary University of London, London, UK.
5Royal College of Art, London, UK.
E-mail: *
October 19th 2022
Abstract. Biomimetic and Bioinspired design is not only a potent resource
for roboticists looking to develop robust engineering systems or understand the
natural world. It is also a uniquely accessible entry point into science and
technology. Every person on Earth constantly interacts with nature, and most
people have an intuitive sense of animal and plant behavior, even without realizing
it. The Natural Robotics Contest is novel piece of science communication that
takes advantage of this intuition, and creates an opportunity for anyone with an
interest in nature or robotics to submit their idea and have it turned into a real
engineering system. In this paper we will discuss the competition’s submissions,
which show how the public thinks of nature as well as the problems people see as
most pressing for engineers to solve. We will then show our design process from
the winning submitted concept sketch through to functioning robot, to offer a case
study in biomimetic robot design. The winning design is a robotic fish which uses
gill structures to filter out microplastics. This was fabricated into an open source
robot with a novel 3D printed gill design. By presenting the competition and the
winning entry we hope to foster further interest in nature-inspired design, and
increase the interplay between nature and engineering in the minds of readers.
Keywords: Bioinspired Design, Robotics, Biomimetics
The Natural Robotics Contest 2
1. Introduction
Bioinspiration is the process of taking observations
from naturally occurring systems and applying it to
synthetic systems. Learning from nature is not new -
for most of human history there was no obvious way to
distinguish where the ‘natural’ world stopped and the
synthetic world began, and ‘bioinspiration’ as a term
would have been somewhat redundant. However, as
many natural processes are pushed to the boundaries of
society and the built environment occupies more of our
reality, a need to resume the process of learning from
nature has been felt within the scientific community.
Moreover, technology now allows us to understand with
far greater detail the processes and structures which
underpin the dynamics of nature, and our improving
understanding of evolution allows greater appreciation
of the efficiencies and performance gains that have
been wrought by eons of natural selection. Natural
materials, movement and behaviour offer the means for
technologists to find approaches that maximise the use
of available resources, rather than relying on extractive
means of increasing performance (e.g. the use of ever
greater energy in producing and operating a system).
Robotics is a field which can draw particular
benefit from the reservoir of evolved knowledge in
the natural world, as it strives to build mechanical
systems which face many of the same challenges as
animals moving through the world. By looking at
nature readers can find new modes of locomotion
[1], understand the limits of performance and how to
overcome them [2], and find small and almost costless
means of improving performance [3]. Bioinspired
design has also driven interest in the benefits of
compliant structures [4] and plays an important role in
the growing field of soft robotics [5]. Biomimetic robots
that directly copy animals can even be used as means to
better understand animals themselves, by functioning
as physical models for biomechanics studies [6].
Nature is a fantastic entry-point for teaching [7];
almost everyone has an intuitive sense for animal
behavior and locomotion from watching anything from
movies to pets, pigeons, squirrels and other ubiquitous
wildlife, even without realizing it. What is often
needed is simply a way to think about what is already
subconsciously known. By holding a bioinspired design
competition, we provided a novel way for people
to engage with creative design outside of a normal
didactic environment, and documenting the winning
design will provide a recent and tangible ‘case study’
to be used in teaching. And it was fun.
In this paper we will describe a public bioinspired
design competition, ‘The Natural Robotics Contest’.
We break down the types of ideas generated by
participants (examples are given in figure 1, rendered
by Dall-E 2 [8] for compactness, with original entries
shown in Appendix A). We will feature a selection
of the best ideas selected by the competition judges
(the authors of this manuscript), before presenting the
process of turning the winning entry into a working
prototype, and displaying the robot in-action.
2. The Natural Robotics Contest
The Natural Robotics Contest is novel piece of science
communication, intended to be an opportunity for
anyone with an interest in nature or robotics to have
their idea turned into a real engineering system. The
brief for the contest was simple - entrants needed to
submit an idea for a robot, inspired by nature, that can
do something to help the world (see Appendix B). The
competition was marketed principally to high school
and university students but entry was open to anyone
interested. It has a deliberately low barrier to entry -
only a simple sketch and description was asked for, so
that it was accessible to entrants from all subjects and
experience levels, and the website was explicit that the
judging panel was looking for creativity and potential
impact, not drawing ability. Over the two months that
the competition was open to submissions, it received
approximately 100 entries.
2.1. Submitted Entries
In the interests of protecting privacy, personal data
was not collected from the entrants beyond an
email address for communication. However, website
analytics provided an insight into the reach and interest
in the competition from around the world (figure
2). The majority of traffic came from the UK and
USA, together accounting for around 50% of the total.
This is to be expected given the outlets the contest
was promoted in, and the language of the website.
The contest was also promoted in German, and as a
consequence the third largest proportion of traffic came
from Germany.
The contest received a wide variety of proposals
taking inspiration from a diverse set of natural systems
(figure 3). There was an even spread of robots
across flight, swimming and terrestrial locomotion
(figure 3B), but a pronounced preference among
participants to design robots which could help to
remove waste from the environment, in particular the
ocean (figure 3C). The second most common type of
design was a robot which provided some form of service
to plant life, whether by pollinating, seed planting
or otherwise monitoring and protecting forests and
similar ecosystems.
While there is not enough space to cover every
entry in this manuscript, some notable entries are
discussed here, with the submitted drawings included
in Appendix A. ‘SkyRanger’ by Teju Sankuratri (figure
The Natural Robotics Contest 3
Figure 1. A selection of top-scoring ideas for bioinspired robots, rendered by Dall-E. A) A robotic fish ingests plastic waste from
the ocean. B) A robotic squirrel plants milkweed seeds. C) A robotic bird patrols a forest to track deforestation. D) A robotic sea
urchin cleans algae from coral and combats acidification with secretions.
Map of Competition Traffic Competition Traffic Country Breakdown
Japan (1%)
Tunisia (1%)
Finland (1%)
Australia (2%)
Spain (2%)
Switzerland (2%)
China (2%)
Canada (2%)
Italy (3%)
France (3%)
Netherlands (3%)
India (5%)
Germany (6%)
United States (26%)
United Kingdom (27%)
Figure 2. Contest web traffic, based on counts of unique users. A) Map of countries from which the contest webpage was accessed.
B) Breakdown by country. The ma jority of traffic came from the UK and the USA.
A1) proposes the use of biomimetic birds as a means
to survey ecosystems and function as an early warning
system for ecological harm. The development of
bird-inspired robots is an active area of research [9],
and while many design concepts have been proposed,
practical application demonstrations remain scarce
and there is significant further research effort needed.
The proposed ‘Ersters’ robot by Elizabeth Ivanova
(figure A2) is an excellent idea that identifies an
important ecosystem service offered by oysters [10],
although the judges noted that in this instance it
was not immediately obvious how a robot could
improve upon the filtration already performed by the
natural animals. The ‘Specialised Anti-Acidification
Sea Urchin’ by ‘The Robotineers’ (figure A3) was
another well-researched idea for an ocean clean-up
technology that was very popular with the judges. Sea
Urchins are tenacious animals with profound effects
on many ecosystems, and harnessing some of their
adaptations to protect coral is an attractive idea.
‘Bumblebot’ by Daniella Clifton (figure A8), is one of
several robotic pollinators proposed among the contest
entries, and echoes the considerable interest in bee-
inspired robots seen in the aerial robotics field, where
one of the smallest and best-known robots is the
Harvard Robobee [11]. The Hermit crab rover by ‘The
Yak Collective’ (figure A5) is a scavenger robot, which
gathers scrap material from its surroundings to build
itself a protective shell. In a somewhat similar vein
is the ‘Milkweed planting squirrel’ by Sue Klefstad
(figure A4), which seeks to emulate the seed burying
behaviour of squirrels to plant milkweed, a plant
which is essential to the lifecycle of many butterfly
(Danainae) species, including the monarch butterfly.
A number of submissions also focused exclusively on
enabling new forms of locomotion to explore the robot’s
surroundings. An example is ‘Spider-Poppins’ by
Maier Fenster (figure A6), which mimics the ballooning
motion of spiders. Though scientific observations of
spider ballooning date back to Charles Darwin [12],
The Natural Robotics Contest 4
Robot Ideas Categorised by Domain
Robot Ideas Categorised by Intended Use
Trash Cleanup
Planting seeds
Protecting Nature
Assisting Humans
Fighting Disease
Fighting pollution
inspired water
flowers like
help animals
bee eat
sea up
make ocean
cases clean
idea lift
off pick
spike things
bats body
Figure 3. Summary of the types of idea submitted to the contest. A) Wordcloud of the descriptions submitted with all contest
entries. B) Design ideas categorised by the domain they move in. C) Robot submissions categorised by intended use. While there
was an even spread of ideas across air, land and water, robots designed to remove waste were by far the most common.
this is is a form of locomotion that has been explored
in new detail by recent biological literature, and is only
now beginning to be fully understood [13].
The submitted designs were all given a mark
from 1-5 by each of the competition judges, and the
design with the highest aggregate mark was selected
as the winner. This year, three designs were tied
for first place based on scores: Eleanor Mackintosh’s
‘Robofish’, Teju Sankuratri’s ‘Sky Ranger’ (figure A1)
and the ‘Specialised Anti-Acidification Sea Urchin’ by
‘The Robotineers’ (figure A3). The winner was selected
from those three by the judges. Eleanor Mackintosh’s
idea for a microplastic filtering fish was ultimately
chosen as the winner (figure 4). This design was chosen
not only for the detailed thought put into the design
and application, but also because the robot’s purpose
as a tool for ocean clean-up represented the most
commonly proposed use case across all competition
entries (figure 3C).
2.2. Analysis of a biomimetic system for removing
Before developing the proposed idea into an engineer-
ing system, it was necessary to gain a better under-
standing of the problem it was trying to solve. Mi-
croplastic pollution is a growing global concern, and
neither the geography nor the impact of the problem
is well understood. Estimates of plastic concentrations
vary widely, due to both a paucity of data and vari-
ability in sampling methods. Predictions by the World
Economic Forum show that plastic could exceed fish
by weight by 2050 [14].
Removing extant ocean microplastic through
robotic filtration is unlikely to be successful. There
is simply no reliable way of distinguishing organic
matter that is vital to the ecosystem such as plankton
and ‘marine snow’ from synthetic pollutants, and it is
difficult to imagine how a cleanup could avoid directly
harming marine life in the process.
Moreover, the scale of removal necessary is likely
beyond the reach of current technology. If we take
the example of one of the largest filter feeding marine
organisms, the basking shark, we can get a sense of
the problem. Basking sharks filter around 30kg of
particulate from the water each day by filtering around
800m3of water per hour [15]. Filtering all ocean
water would take 100 billion shark-years, and even if
a all of the 30kg of particulate matter were plastic (in
actuality, microplastics are found at concentrations of
a few particles per liter [16]), it would take 1 million
basking sharks to filter out the 10 million tonnes [17]
of plastic entering the ocean each year.
Even systems engineered to remove plastic at scale
struggle. Last year, in collaboration with researchers
The Natural Robotics Contest 5
Fish gills work by:
1- mouth open, gills closed, internal cavity
as wide as possible
2- cavity fills with water, mouth closes, gills
open as the floor of cavity is compressed to
force water over gills
By Eleanor Mackintosh
Gills attached to each
other on the outer
edge with layers of
offset fine mesh to
catch microplastics
Layers of
Figure 4. The winning contest entry, by Eleanor Mackintosh: A robotic fish which uses gills to filter and sample microplastic
pollution in aquatic ecosystems.
The Natural Robotics Contest 6
in the United Kingdom and Germany, Hohn et al.[18]
published an analysis of what it would take for the
Ocean Cleanup to collect only the floating plastic in
the largest five gyres. Hohn et al. took the current
amount of plastic in the ocean, added annual inputs,
and compared it with how much plastic the Ocean
Cleanup’s successful pilot collected. To clean up a
fraction of one percent of the total, the Ocean Cleanup
would have to run nonstop until 2150. Even when
Hohn et al. artificially increased the fleet to 200
booms, the project still only recovered five percent of
the floating plastic [18]. However, while immediate
removal of ocean plastic is not feasible, targeted
removal efforts do have a significant effect. The
aforementioned Ocean cleanup is currently deploying
’interceptors’ to the world’s most polluted rivers [19],
to prevent plastic from reaching the ocean.
So this is not to say that the problem is
intractable, nor that there is no role for technology
- the opposite is true. There is an immediate need for
better data on microplastics, as the location of the vast
majority of the plastic waste that has been dumped
into aquatic ecosystems is unknown, and robots could
play a leading role in this task. Targeted cleanups are
effective mitigations [20], but need better data in order
to be focused effectively and maximise resource use.
This is especially true of freshwater ecosystems, which
account for only 4% of published research on plastic
waste [21]. A microplastic-filtering robot, particularly
one which could access areas of the water inaccessible
to humans, would be very useful as a data collection
tool. This was identified by the competition winner in
her entry.
3. Creating the Winning Design
The winning design for a pollution-filtering robot with
fish-like gills, was developed into a 442 mm long
robotic fish (figure 5A-B), which moves by body-
caudal fin undulation, with a carangiform propulsion
mode. The winner of the contest was communicated
to participants via an online video , which shows the
robot in action. The robot has a large head cavity with
an openable mouth and sets of gills that contain a 2 mm
nylon mesh. The robot is remotely controlled, although
it has been equipped with the sensors necessary for
basic autonomy in future iterations.
Undulation of the tail is driven by motorised
pushrods (made from 0.5 mm diameter music wire)
connected to the base of the tail, a design which
was used to good effect by [22]. Unlike [22], the
left and right pushrods are driven by separate motors
(figure 5C), which both allows for steering via changing
the relative amplitude of the left and right motors,
and increased power while still using a popular and
affordable smart servo model (XL330-M288). Finally
using separate motors allows for a future iteration
of the fish robot to make use of antagonistic co-
contraction of the two swim motors, which has benefits
to swimming efficiency [23]. The robot is designed to
be neutrally buoyant and uses actuated pectoral fins
to control pitch and depth.
It was decided that the robot should only use
affordable off-the-shelf components and manufacturing
techniques, so that the design is accessible to all. As
such, the robot is entirely 3D printed with a low-cost
fused deposition manufacturing (FDM) printer (Prusa
Mini+, 0.4 mm nozzle), with the control electronics,
battery and propulsion motors contained in a sealed
‘tail’ unit, onto which the ‘head’ of the robot is
attached via a snap-fit joint (figure 5B). This modular
design was chosen so that the head could be readily
changed to meet different gill arrangements in the
The gill structures in ram-filter feeding marine
animals typically have structures which obstruct the
internal water flow. This creates trapped vortices
behind each gill raker which aid the collection of
particulate matter with less impediment to the flow of
water through the gill structure [24]. To achieve this
in a robot, we 3D printed an array of gill plates, and
created an interstitial mesh by pausing the print and
inserting nylon mesh between layers (figure 5D). Each
gill rotates around a rod, and the gill array is opened
and closed via a pushrod connected to the leading gill.
A gill array was bisected along the sagittal plane and
affixed to a transparent sheet (figure 6) for testing in an
86 mm wide water flume (HM 160, GUNT Ger¨atebau
GmbH). A 0.8 l/s flow rate was used, giving a mean
water velocity of 8 cm/s at the mouth of the fish.
When opened, the gill array passively collects incoming
particles (figure 6) and arrests their locomotion at the
mesh, where they eventually drop to the stagnant area
of flow at the base of the robot without accruing and
obstructing the gills.
Neutral buoyancy is achieved by modifying the
infill density of all 3D printed parts, such that the net
weight of the part is as close to equal to its displaced
volume as can be achieved without compromising
watertightness. The majority of the robot is printed
in ABS plastic which is dipped in acetone to seal
the micropores resulting from the FDM printing
process, which would otherwise cause leaks. For
aesthetic reasons, selected components and additional
accents are printed in phosphorescent PLA (figure
5E). The two motors which are outside the watertight
tail section were disassembled and waterproofed by
covering circuitry with an acrylic conformal coating
(Electrolube Acrylic Protective Lacquer) and filling the
The Natural Robotics Contest 7
Gill Raker
Pectoral Fins
Gill / Mouth Motor
Pectoral Fin Motor
Particulate Mesh
Tail Fin Motor
Caudal Fin
Tail Fin Actuation Rod
Sensors (Light and Turbidity)
Head-Tail Length: 442 mm
Battery and Microcontroller
Watertight Tail Unit
Flooded Head Unit
Figure 5. The fabricated contest winner, a microplastic-collecting robotic fish. A) Image of the completed fish. B) CAD render of
the fish design, showing the modular design, with a separate, watertight unit for propulsion, power and control, and a swappable
head unit for different missions. C) Diagram of the robot, showing the internal mechanics, including location of actuation motors,
and the position of gill rakers and mesh for filtering. D) Image of the gill rakers, with mesh integrated directly into the 3D printing
process. E) Image of the fish showing phosphorescent accents. F) Image of the fish swimming in a lake.
The Natural Robotics Contest 8
Figure 6. Demonstration of the fish’s gills, used for filtering plastic particles. The robot’s head was bisected along the sagittal
plane and placed in a water flume. In all images, water flow direction is from left to right. A) Top view, showing gill angle (all gills
are identically sized. B) Front view, showing mouth. C) internal view, showing particles trapped against gills by vortices shed from
internal edges of the gill plates.
entire servo cavity with non-conductive grease (Liqui
Moly 3140). This method performed well and after
an initial gasket failure that was repared, no ingress
of liquid was observed in the tests performed, which
included throwing the fish into the water from the shore
around 10 times.
The robot uses four Dynamixel XL330 smart
servos for actuation, with two XL330-M288 motors
powering the caudal fin, and two XL330-M077 motors
(with lower torque and higher speed than the M288
model) controlling the gills and pectoral fins (figure
5C). The robot is controlled over WiFi using a remote
(Xbox One controller), via an Arduino Nano33 IoT
microcontroller, which contains an LSM6DS3 inertial
measurement unit. A turbidity sensor is placed
inside the mouth of the fish to sense particulate
concentration, and an exterior light/colour sensor
(TCS34725) provides basic navigation cues. The
robot is powered by a 5000mAh battery (Auskang
USB-C power pack). The USB serial port of the
microncontroller is connected to a wire, to allow easy
reprogramming of the fish during testing (figure 5F)
without opening watertight compartments. This will
be removed in future versions of the robot.
The robot was testing in an outdoor lake in
Guildford (UK), and demonstrated effective swimming
and steering on the water surface. The typical
swimming speed was 5 cm/s at a tailbeat frequency
of 2 Hz, with the speed limited by the high drag
of the robot’s filtering head and the relatively small
propulsion motors (3 W of propulsion power versus
10W in [22]). However speed could be improved with
a better optimisation of the caudal fin and better
matching of the robot’s tail stiffness to the inertia of
its head in future iterations. The robot was able to
submerge, but a tendency of the mouth cavity to trap
air was an issue. A future iteration would benefit from
the provision of buoyancy control [25]. Fortunately,
there is ample space in the head cavity for this (figure
3.1. Future Work
Currently, the robot is able to ingest and retain
particulates, but has no means of analysing them
directly. To be an effective tool for ocean sampling,
this would need to be automated. As the tools to
analyse microplastics (e.g. Fourier-transform infrared
spectroscopy equipment) require rigid, calibrated
optics, and do not currently minaturise well. The
authors intend to develop a larger floating docking
station, that could pump out collected material into
a sampling chamber and clean the interior of the robot
for a new sampling mission. Collected material could
then be analysed while further samples are collected.
This base station could also function as a charging
point for the robot, as well as a repeater for wireless
communications, ameliorating the difficulty of signal
transmission through water.
4. Conclusion
The Natural Robotics Contest has collected ideas from
around the world, and shows not only the desire among
the public to improve nature with technology, but also
a thoughtful approach to looking at nature among
participants, with many innovate ideas on display.
The winning robot has realised the design features
proposed by its originator, and now offers a promising
new application for biomimetic underwater robots,
that will be developed further in future. This is
the first iteration of the Natural Robotics Contest,
and the authors plan to repeat the contest in coming
years, with future version of the contest featuring
more detailed design challenges that represent the most
pressing needs of the day. By building a library of
bioinspired design year on year, the contest will become
a resource for those who wish to harness nature to
improve the world.
The Natural Robotics Contest 9
5. Contribution Statement
The contest and all associated graphic/web design
was created by RS. RS, KZ, SS, SA and RZ judged
the contest. The winning entry was designed and
fabricated by RS, LS, and RZ. RS prepared the paper,
with all authors contributing to the final version.
6. Data Availability
More information on the competition is available
on its website:,
and the CAD design for the presented robot is
available for download:
fish-5. The winner of the contest was announced
via an online video, which can be viewed here: Any other information can be
made available upon request.
7. Acknowledgments
The authors would like to thank all the entrants
to the competition for their thoughtful and creative
submissions. Thanks also go to Fabian Franke and
the COMLAB4 team for helping to dream up the
contest. This project was funded by the Alexander von
Humboldt Foundation, the International Journalist’s
Programmes, and the University of Surrey’s Teaching
Innovation Fund.
The Natural Robotics Contest 10
Appendix A. Selected Competition Entries
In recognition of the effort that went into producing designs by the contest’s participants, we have included
several notable entries as an appendix to this paper. While it was not possible to include every submission, the
judges would like to note that almost every entry considered had merit, and it was ultimately a difficult decision.
Figure A1. ’Sky Ranger’, a submission by Teju Sankuratri. The proposed robot is bird inspired, and intended to track and combat
The Natural Robotics Contest 11
Figure A2. A robotic oyster used to filter/clean water, by Elizabeth Ivanova.
Figure A3. Sea Urchin-inspired submission by ’The Robotineers’. The pictured design is intended to protect corals by removing
problematic algae and secreting alkaline substances.
The Natural Robotics Contest 12
Figure A4. Contest Submission by Sue Klefstad. The pictured design is intended to employ the seed burying behaviours of squirrels
as a way to plant Milkweeds.
Figure A5. Contest Submission by ’The Yak Collective’. The pictured design is intended to scavenge material to form a protective
shell around a mobile rover.
The Natural Robotics Contest 13
Figure A6. Contest Submission by Maier Fenster. A miniature robot emulates the ballooning behviour of spiders to move around
its environment.
Figure A7. Contest Submission by Elizabeth Isaac. A miniature robot emulates the ballooning behaviour of spiders to move
around its environment.
The Natural Robotics Contest 14
Figure A8. Contest Submission by Daniella Clifton. A robotic bumblebee pollinates plants
The Natural Robotics Contest 15
Figure A9. Contest Submission by Irina Putchenko. A robotic mosquito allows easier access to blood samples in medicine.
The Natural Robotics Contest 16
Appendix B. Natural Robotics Contest Competition Advertisement
Are you fascinated by nature’s solutions to
life’s challenges? Have you ever thought of a
way to use bioinspired design to improve the
Perhaps a robotic woodpecker that checks
trees for disease? Or a mechanical falcon that
protects sea turtle eggs?
This contest is a chance for you to have your
ideas turned into reality!
All you need is a short description of your
idea and a drawing. The competition is open
until June 30th 2022.
The winning entry will be turned into
a real prototype by a team of expert
robotics researchers!
Find out more and send us your idea at
Figure B1. The contest was advertised across a variety of channels, including digital news media, university social media, Maker/Art
forums, STEM outreach charities, and direct word-of-mouth. The flyer above was circulated widely for display on noticeboards and
in email newsletters.
The Natural Robotics Contest 17
[1] Zufferey R, Siddall R, Armanini SF, Kovac M. Between
Sea and Sky: Aerial Aquatic Locomotion in Miniature
Robots. Springer; 2022.
[2] Williams SB, Tan H, Usherwood JR, Wilson AM. Pitch
then power: limitations to acceleration in quadrupeds.
Biology letters. 2009;5(5):610-3.
[3] Fish F, Lauder GV. Passive and active flow control by
swimming fishes and mammals. Annu Rev Fluid Mech.
[4] Siddall R, Fukushima T, Bardhi D, Perteshoni B, Morina
A, Hasimja E, et al. Compliance, mass distribution
and contact forces in cursorial and scansorial locomotion
with biorobotic physical models. Advanced Robotics.
[5] Kim S, Laschi C, Trimmer B. Soft robotics: a bioin-
spired evolution in robotics. Trends in biotechnology.
[6] Siddall R, Byrnes G, Full RJ, Jusufi A. Tails stabilize
landing of gliding geckos crashing head-first into tree
trunks. Communications biology. 2021;4(1):1-12.
[7] Full RJ, Bhatti H, Jennings P, Ruopp R, Jafar T,
Matsui J, et al. Eyes Toward Tomorrow Program
Enhancing Collaboration, Connections, and Community
Using Bioinspired Design. Integrative and comparative
biology. 2021;61(5):1966-80.
[8] Ramesh A, Dhariwal P, Nichol A, Chu C, Chen M.
Hierarchical text-conditional image generation with clip
latents. arXiv preprint arXiv:220406125. 2022.
[9] Zufferey R, Barbero JT, Talegon DF, Nekoo SR, Acosta JA,
Ollero A. How ornithopters can perch autonomously on
a branch. arXiv preprint arXiv:220707489. 2022.
[10] Zu Ermgassen PS, Spalding MD, Grizzle RE, Brumbaugh
RD. Quantifying the loss of a marine ecosystem service:
filtration by the eastern oyster in US estuaries. Estuaries
and coasts. 2013;36(1):36-43.
[11] Ma KY, Chirarattananon P, Fuller SB, Wood RJ.
Controlled flight of a biologically inspired, insect-scale
robot. Science. 2013;340(6132):603-7.
[12] Gorham PW. Ballooning spiders: the case for electrostatic
flight. arXiv preprint arXiv:13094731. 2013.
[13] Cho M, Koref IS. The Importance of a Filament-like
Structure in Aerial Dispersal and the Rarefaction Effect
of Air Molecules on a Nanoscale Fiber: Detailed Physics
in Spiders’ Ballooning. Integrative and Comparative
Biology. 2020 06;60(4):864-75.
[14] Agenda I. The New Plastics Economy Rethinking the
future of plastics. In: The World Economic Forum:
Geneva, Switzerland; 2016. p. 36.
[15] Fossi MC, Coppola D, Baini M, Giannetti M, Guerranti C,
Marsili L, et al. Large filter feeding marine organisms
as indicators of microplastic in the pelagic environment:
the case studies of the Mediterranean basking shark
(Cetorhinus maximus) and fin whale (Balaenoptera
physalus). Marine environmental research. 2014;100:17-
[16] Cressey D. The plastic ocean. Nature. 2016;536(7616):263-
[17] Jambeck JR, Geyer R, Wilcox C, Siegler TR, Perryman M,
Andrady A, et al. Plastic waste inputs from land into
the ocean. Science. 2015;347(6223):768-71.
[18] Hohn S, Acevedo-Trejos E, Abrams JF, de Moura JF,
Spranz R, Merico A. The long-term legacy of plastic
mass production. Science of the Total Environment.
[19] Williams L. Rid the rivers of rubbish [Plastics Pollution].
Engineering & Technology. 2020;15(10):64-7.
[20] 30th Anniversary International Coastal Cleanup. Ocean
Conservancy; 2016.
[21] Microplastics in freshwater and soil: an evidence synthesis.
The Royal Society; 2019.
[22] van den Berg SC, Scharff RB, Rus´ak Z, Wu J. OpenFish:
Biomimetic design of a soft robotic fish for high speed
locomotion. HardwareX. 2022:e00320.
[23] Lin YH, Siddall R, Schwab F, Fukushima T, Banerjee H,
Baek Y, et al. Modeling and control of a soft robotic
fish with integrated soft sensing. Advanced Intelligent
[24] Sanderson SL, Roberts E, Lineburg J, Brooks H. Fish
mouths as engineering structures for vortical cross-step
filtration. Nature communications. 2016;7(1):1-9.
[25] Zufferey R, Siddall R, Armanini SF, Kovac M. Multirotor
Aircraft and the Aquatic Environment. In: Between
Sea and Sky: Aerial Aquatic Locomotion in Miniature
Robots. Springer; 2022. p. 197-211.
ResearchGate has not been able to resolve any citations for this publication.
Full-text available
We present OpenFish: an open source soft robotic fish which is optimized for speed and efficiency. The soft robotic fish uses a combination of an active and passive tail segment to accurately mimic the thunniform swimming mode. Through the implementation of a novel propulsion system that is capable of achieving higher oscillation frequencies with a more sinusoidal waveform, the open-source soft robotic fish achieves a top speed of 0.85m/s. Hereby, it outperforms the previously reported fastest soft robotic fish by 27%. Besides the propulsion system, the optimization of the fish morphology played a crucial role in achieving this speed. In this work, a detailed description of the design, construction and customization of the soft robotic fish is presented. Hereby, we hope this open-source design will accelerate future research and developments in soft robotic fish.
Full-text available
Animals use diverse solutions to land on vertical surfaces. Here we show the unique landing of the gliding gecko, Hemidactylus platyurus. Our high-speed video footage in the Southeast Asian rainforest capturing the first recorded, subcritical, short-range glides revealed that geckos did not markedly decrease velocity prior to impact. Unlike specialized gliders, geckos crashed head-first with the tree trunk at 6.0 ± 0.9 m/s (~140 body lengths per second) followed by an enormous pitchback of their head and torso 103 ± 34° away from the tree trunk anchored by only their hind limbs and tail. A dynamic mathematical model pointed to the utility of tails for the fall arresting response (FAR) upon landing. We tested predictions by measuring foot forces during landing of a soft, robotic physical model with an active tail reflex triggered by forefoot contact. As in wild animals, greater landing success was found for tailed robots. Experiments showed that longer tails with an active tail reflex resulted in the lower adhesive foot forces necessary for stabilizing successful landings, with a tail shortened to 25% requiring over twice the adhesive foot force.
Full-text available
The goal of our i4’s Toward Tomorrow Program is to enrich the future workforce with STEM by providing students with an early, inspirational, interdisciplinary experience fostering inclusive excellence. We attempt to open the eyes of students who never realized how much their voice is urgently needed by providing an opportunity for involvement, imagination, invention, and innovation. Students see how what they are learning, designing, and building matters to their own life, community, and society. Our program embodies convergence by obliterating artificially created, disciplinary boundaries to go far beyond STEM or even STEAM by including artists, designers, social scientists, and entrepreneurs collaborating in diverse teams using scientific discoveries to create inventions that could shape our future. Our program connects two recent revolutions by amplifying Bioinspired Design with the Maker Movement and its democratizing effects empowering anyone to innovate and change the world. Our course is founded in original discovery. We explain the process of biological discovery and the importance of scaling, constraints, and complexity in selecting systems for bioinspired design. By spotlighting scientific writing and publishing, students become more science literate, learn how to decompose a biology research paper, extract the principles, and then propose a novel design by analogy. Using careful, early scaffolding of individual design efforts, students build the confidence to interact in teams. Team building exercises increase self-efficacy and reveal the advantages of a diverse set of minds. Final team video and poster project designs are presented in a public showcase. Our program forms a student-centered creative action community comprised of a large-scale course, student-led classes, and a student-created university organization. The program structure facilitates a community of learners that shifts the students' role from passive knowledge recipients to active co-constructors of knowledge being responsible for their own learning, discovery, and inventions. Students build their own shared database of discoveries, classes, organizations, research openings, internships, and public service options. Students find next step opportunities so they can see future careers. Description of our program here provides the necessary context for our future publications on assessment that examine 21st century skills, persistence in STEM, and creativity.
Full-text available
Locomotion in unstructured and irregular environments is an enduring challenge in robotics. This is particularly true at the small scale, where relative obstacle size increases, often to the point that a robot is required to climb and transition both over obstacles and between locomotion modes. In this paper, we explore the efficacy of different design features, using ‘morphological intelligence’, for mobile robots operating in rugged terrain, focusing on the use of active and passive tails and changes in mass distribution, as well as elastic suspensions of mass. We develop an initial prototype whegged robot with a compliant neck and test its obstacle traversal performance in rapid locomotion with varying its mass distribution. Then we examine a second iteration of the prototype with a flexible tail to explore the effect of the tail and mass distribution in ascending a slope and traversing obstacles. Based on observations from these tests, we develop a new platform with increased performance and a fin ray wheel-leg design and present experiments on traversing large obstacles, which are larger than the robot's body, of this platform with tails of varying compliance. This biorobotic platform can assist with generating and testing hypotheses in robotics-inspired biomechanics of animal locomotion.
Full-text available
Soft robotics can be used not only as a means of achieving novel, more lifelike forms of locomotion, but also as a tool to understand complex biomechanics through the use of robotic model animals. Herein, the control of the undulation mechanics of an entirely soft robotic subcarangiform fish is presented, using antagonistic fast-PneuNet actuators and hyperelastic eutectic gallium–indium (eGaIn) embedded in silicone channels for strain sensing. To design a controller, a simple, data-driven lumped parameter approach is developed, which allows accurate but lightweight simulation, tuned using experimental data and a genetic algorithm. The model accurately predicts the robot’s behavior over a range of driving frequencies and a range of pressure amplitudes, including the effect of antagonistic co-contraction of the soft actuators. An amplitude controller is prototyped using the model and deployed to the robot to reach the setpoint of a tail-beat amplitude using fully soft and real-time strain sensing.
Full-text available
Suspension-feeding fishes such as goldfish and whale sharks retain prey without clogging their oral filters, whereas clogging is a major expense in industrial crossflow filtration of beer, dairy foods and biotechnology products. Fishes' abilities to retain particles that are smaller than the pore size of the gill-raker filter, including extraction of particles despite large holes in the filter, also remain unexplained. Here we show that unexplored combinations of engineering structures (backward-facing steps forming d-type ribs on the porous surface of a cone) cause fluid dynamic phenomena distinct from current biological and industrial filter operations. This vortical cross-step filtration model prevents clogging and explains the transport of tiny concentrated particles to the oesophagus using a hydrodynamic tongue. Mass transfer caused by vortices along d-type ribs in crossflow is applicable to filter-feeding duck beak lamellae and whale baleen plates, as well as the fluid mechanics of ventilation at fish gill filaments.
This book reports on the state of the art in the field of aerial-aquatic locomotion, focusing on the main challenges concerning the translation of this important ability from nature to synthetic systems, and describing innovative engineering solutions that have been applied in practice by the authors at the Aerial Robotics Lab of Imperial College London. After a general introduction to aerial-aquatic locomotion in nature, and a summary of the most important engineering achievements, the book introduces readers to important physical and mathematical aspects of the multimodal locomotion problem. Besides the basic physics involved in aerial-aquatic locomotion, the role of different phenomena happening in fluids, or those due to structural mechanics effects or to power provision, are presented in depth, across a large dimension range, from millimeters to hundreds of meters. In turn, a practice-oriented discussion on the obstacles and opportunities of miniaturization, for both robots and animals is carried out. This is followed by applied engineering considerations, which describe relevant hardware considerations involved in propulsion, control, communication and fabrication. Different case studies are analyzed in detail, reporting on the latest research carried out by the authors, and covering topics such as propulsive aquatic escape, the challenging mechanics of water impact, and a hybrid sailing and flying aircraft. Offering extensive and timely information on the design, construction and operation of small-scale robots, and on multimodal locomotion, this book provides researchers, students and professionals with a comprehensive and timely reference guide to the topic of aerial-aquatic locomotion, and the relevant bioinspired approaches. It is also expected to inspire future research and foster a stronger multidisciplinary discussion in the field.
Mismanaged plastic waste is transported via rivers or city drains into the ocean where it accumulates in coastal sediments, ocean gyres and the deep ocean. Plastic harms marine biota and may ultimately return to humans via the food chain. Private initiatives proposing to collect plastic from the sea and rivers have gained widespread attention, especially in the media. However, few of these methods are proven concepts and it remains unclear how effective they are. Here we estimate the amount of plastic in the global surface ocean to assess the long-term legacy of plastic mass production, calculate the time required to clean up the oceans with river barriers and clean up devices, and explore the fate of collected plastic waste. We find that the projected impact of both single and multiple clean up devices is very modest. A significant reduction of plastic debris in the ocean can be only achieved with collection at rivers or with a combination of river barriers and clean up devices. We also show that the incineration and production of plastic has a significant long-term effect on the global atmospheric carbon budget. We conclude that a combination of reduced plastic emissions and reinforced collection is the only way to rid the ocean of plastic waste.
Synopsis Many flying insects utilize a membranous structure for flight, which is known as a “wing.” However, some spiders use silk fibers for their aerial dispersal. It is well known that spiders can disperse over hundreds of kilometers and rise several kilometers above the ground in this way. However, little is known about the ballooning mechanisms of spiders, owing to the lack of quantitative data. Recently, Cho et al. discovered previously unknown information on the types and physical properties of spiders’ ballooning silks. According to the data, a crab spider weighing 20 mg spins 50–60 ballooning silks simultaneously, which are about 200 nm thick and 3.22 m long for their flight. Based on these physical dimensions of ballooning silks, the significance of these filament-like structures is explained by a theoretical analysis reviewing the fluid-dynamics of an anisotropic particle (like a filament or a high-slender body). (1) The filament-like structure is materially efficient geometry to produce (or harvest, in the case of passive flight) fluid-dynamic force in a low Reynolds number flow regime. (2) Multiple nanoscale fibers are the result of the physical characteristics of a thin fiber, the drag of which is proportional to its length but not to its diameter. Because of this nonlinear characteristic of a fiber, spinning multiple thin ballooning fibers is, for spiders, a better way to produce drag forces than spinning a single thick spider silk, because spiders can maximize their drag on the ballooning fibers using the same amount of silk dope. (3) The mean thickness of fibers, 200 nm, is constrained by the mechanical strength of the ballooning fibers and the rarefaction effect of air molecules on a nanoscale fiber, because the slip condition on a fiber could predominate if the thickness of the fiber becomes thinner than 100 nm.