A dual caudal-fin miniature robotic fish with an integrated oscillation and jet propulsive mechanism
This paper presents the development of a biomimetic robotic fish that uses an integrated oscillation
and jet propulsive mechanism to enable good swimming performance for small robotic fish. The
designed robotic fish is driven by two caudal fins that flap oppositely, which are equipped in
parallel at the fish tail. The propulsive mechanism of dual caudal fins is characterized by using
numerical analysis, in which the distance between the two caudal fins is a key factor to the
integrated mechanism and plays an important role to swimming performance. This finding has been
further verified by experiments performed on a m...
Source: Bioinspiration and Biomimetics - March 26, 2018 Category: Science Authors: Pan Liao, Shiwu Zhang and Dong Sun Source Type: research
A simple bipedal model for studying control of gait termination
We study the control of human gait termination with a simple bipedal locomotion model. Several
control strategies have been proposed for gait termination. However, the relative importance of
these strategies has not been evaluated in models of human gait. Here we extend the bipedal spring
mass walking model in a least parameter fashion and study three explicit control strategies for gait
termination, including the shortening of the final step, braking at the ankle, and extending the
knee. Applying the strategies separately, we find that only braking at the ankle reduces the
propulsive force enough to transition into ...
Source: Bioinspiration and Biomimetics - March 26, 2018 Category: Science Authors: Yasuyuki Suzuki and Hartmut Geyer Source Type: research
A direct optic flow-based strategy for inverse flight altitude estimation with monocular vision and
IMU measurements
With tiny and limited nervous systems, insects demonstrate a remarkable ability to fly through
complex environments. Optic flow has been identified to play a crucial role in regulating flight
conditions and navigation in flies and bees. In robotics, optic flow has been widely studied thanks
to the low computational requirements. However, with only monocular visual information, optic flow
is inherently devoid of a scale factor required for estimating the absolute distance. In this paper,
we propose a strategy for estimating the flight altitude of a flying robot with a ventral camera by
combining the optic flow with me...
Source: Bioinspiration and Biomimetics - March 20, 2018 Category: Science Authors: Pakpong Chirarattananon Source Type: research
White reflection from cuttlefish skin leucophores
The highly diverse and changeable body patterns of cephalopods require the production of whiteness
of varying degrees of brightness for their large repertoire of communication and camouflage
behaviors. Leucophores are structural reflectors that produce whiteness in cephalopods; they are
dermal aggregates of numerous leucocytes containing spherical leucosomes ranging in diameter from
200 –2000 nm. In Sepia officinalis leucophores, leucocytes always occur in various combinations with
iridocytes, cells containing plates that function as Bragg stacks to reflect light of particular
wavelengths. Both spheres and plates...
Source: Bioinspiration and Biomimetics - March 20, 2018 Category: Science Authors: Roger T Hanlon, Lydia M M äthger, George R R Bell, Alan M Kuzirian and Stephen L Senft Source Type: research
Bioinspired wingtip devices: a pathway to improve aerodynamic performance during low Reynolds number
flight
Birds are highly capable and maneuverable fliers, traits not currently shared with current small
unmanned aerial vehicles. They are able to achieve these flight capabilities by adapting the shape
of their wings during flight in a variety of complex manners. One feature of bird wings, the primary
feathers, separate to form wingtip gaps at the distal end of the wing. This paper presents
bio-inspired wingtip devices with varying wingtip gap sizes, defined as the chordwise distance
between wingtip devices, for operation in low Reynolds number conditions of Re = 100 000, where
many bird species operate. Lift ...
Source: Bioinspiration and Biomimetics - March 20, 2018 Category: Science Authors: Michael Lynch, Boris Mandadzhiev and Aimy Wissa Source Type: research
Effects of flexibility and aspect ratio on the aerodynamic performance of flapping wings
In the current study, we experimentally investigated the flexibility effects on the aerodynamic
performance of flapping wings and the correlation with aspect ratio at angle of attack α = 45°.
The Reynolds number based on the chord length and the wing tip velocity is maintained at
Re = 5.3 × 10 3 . Our result for compliant wings with an aspect ratio of 4 shows that wing
flexibility can offer improved aerodynamic performance compared to that of a rigid wing. Flexible
wings are found to offer higher lift-to-drag ratios; in particular, there is significant reduction
in drag with little ...
Source: Bioinspiration and Biomimetics - March 14, 2018 Category: Science Authors: Junjiang Fu, Xiaohui Liu, Wei Shyy and Huihe Qiu Source Type: research
Model-based observer and feedback control design for a rigid Joukowski foil in a K ármán vortex
street
Obstacles and swimming fish in flow create a wake with an alternating left/right vortex pattern
known as a K ármán vortex street and reverse Kármán vortex street, respectively. An energy-efficient
fish behavior resembling slaloming through the vortex street is called K ármán gaiting. This paper
describes the use of a bioinspired array of pressure sensors on a Joukowski foil to estimate and
control flow-relative position in a K ármán vortex street using potential flow theory, recursive
Bayesian filtering, and trajectory-tracking feedback control. The Joukowski foil is fixed in
downstream position in a flowing ...
Source: Bioinspiration and Biomimetics - March 14, 2018 Category: Science Authors: Brian A Free and Derek A Paley Source Type: research
Spine morphology and energetics: how principles from nature apply to robotics
Inspired by the locomotive advantages that an articulated spine enables in quadrupedal animals, we
explore and quantify the energetic effect that an articulated spine has in legged robots. We compare
two model instances of a conceptual planar quadruped: one with a traditional rigid main body and one
with an articulated main body with an actuated spinal joint. Both models feature four distinct legs,
series elastic actuation, distributed mass in all body segments, and limits on actuator torque and
speed. Using optimal control to find the energetically optimal joint trajectories, actuator inputs,
and footfall timing, we...
Source: Bioinspiration and Biomimetics - March 14, 2018 Category: Science Authors: Yevgeniy Yesilevskiy, William Yang and C David Remy Source Type: research
Bio-inspired all-optical artificial neuromast for 2D flow sensing
We present the design, fabrication and testing of a novel all-optical 2D flow velocity sensor,
inspired by a fish lateral line neuromast. This artificial neuromast consists of optical fibres
inscribed with Bragg gratings supporting a fluid force recipient sphere. Its dynamic response is
modelled based on the Stokes solution for unsteady flow around a sphere and found to agree with
experimental results. Tuneable mechanical resonance is predicted, allowing a deconvolution scheme to
accurately retrieve fluid flow speed and direction from sensor readings. The optical artificial
neuromast achieves a low frequency threshol...
Source: Bioinspiration and Biomimetics - February 27, 2018 Category: Science Authors: Ben J Wolf, Jonathan A S Morton, William N MacPherson and Sietse M van Netten Source Type: research
Design and fabrication of a multifocal bionic compound eye for imaging
Miniaturized bionic compound eyes featured with multi-aperture imaging have potential applications
in the areas of micro opto-electro-mechanical-system. In this manuscript, we present a novel
structure of the bionic compound eye with multiple focal lengths consists of an array of individual
lenses with 1000 µ m diameter. The simulation results of the designed multifocal bionic compound eye
(MBCE) with two focal lengths of 190 mm and 44.4 mm demonstrate excellent two-order focusing
abilities. Moving mask exposure technology was used to fabricate the designed MBCE with the
corresponding imaging experiments conduc...
Source: Bioinspiration and Biomimetics - February 27, 2018 Category: Science Authors: Axiu Cao, Jiazhou Wang, Hui Pang, Man Zhang, Lifang Shi, Qiling Deng and Song Hu Source Type: research
Moth-eye mimetic cytocompatible bactericidal nanotopography: a convergent design
This study demonstrates
the bactericidal activity and cytocompatibility of the moth-eye mimetic topography produced by
thermal polymer nanoimprinting. The moth-eye topography was found to have bactericidal capabilities
against Gram negative and Gram positive bacteria. Electron microscopy imaging revealed the
bactericidal effect caused by mechanical rupture of the bacteria wall inflicted by the topography on
the adhered cells. The cytocompatibility of the surfaces was evidenced by assessing the
proliferation and morphology of keratinocytes cultured on the nanotopography. The technology meets
important needs in medica...
Source: Bioinspiration and Biomimetics - February 27, 2018 Category: Science Authors: Felipe Viela, Iv án Navarro-Baena, Jaime J Hernández, Manuel R Osorio and Isabel Rodríguez Source Type: research
A novel rapid additive manufacturing concept for architectural composite shell construction inspired
by the shell formation in land snails
State-of-the-art rapid additive manufacturing (RAM) —specifically fused filament fabrication
(FFF) —has gained popularity among architects, engineers and designers for the quick prototyping of
technical devices, the rapid production of small series and even the construction scale fabrication
of architectural elements. The spectrum of producible shapes and the resolution of detail, however,
are determined and constrained by the layer-based nature of the fabrication process. These aspects
significantly limit FFF-based approaches for the prefabrication and in situ fabrication of free-form
shells at the architectural...
Source: Bioinspiration and Biomimetics - February 16, 2018 Category: Science Authors: B Felbrich, F Wulle, C Allgaier, A Menges, A Verl, K-H Wurst and J H Nebelsick Source Type: research
Classifying vortex wakes using neural networks
Unsteady flows contain information about the objects creating them. Aquatic organisms offer
intriguing paradigms for extracting flow information using local sensory measurements. In contrast,
classical methods for flow analysis require global knowledge of the flow field. Here, we train
neural networks to classify flow patterns using local vorticity measurements. Specifically, we
consider vortex wakes behind an oscillating airfoil and we evaluate the accuracy of the network in
distinguishing between three wake types, 2S, 2P + 2S and 2P + 4S. The network uncovers the
salient features of each wake t...
Source: Bioinspiration and Biomimetics - February 16, 2018 Category: Science Authors: Brendan Colvert, Mohamad Alsalman and Eva Kanso Source Type: research
Laser Doppler sensing for blood vessel detection with a biologically inspired steerable needle
Puncturing blood vessels during percutaneous intervention in minimally invasive brain surgery can be
a life threatening complication. Embedding a forward looking sensor in a rigid needle has been
proposed to tackle this problem but, when using a rigid needle, the procedure needs to be
interrupted and the needle extracted if a vessel is detected. As an alternative, we propose a novel
optical method to detect a vessel in front of a steerable needle. The needle itself is based on a
biomimetic, multi-segment design featuring four hollow working channels. Initially, a laser Doppler
flowmetry probe is characterized in a ti...
Source: Bioinspiration and Biomimetics - February 16, 2018 Category: Science Authors: V Virdyawan, M Oldfield and F Rodriguez y Baena Source Type: research
Multichannel spectrometers in animals
Multispectral, hyperspectral, polarimetric, and other types of multichannel imaging spectrometers
are coming into common use for a variety of applications, including remote sensing, material
identification, forensics, and medical diagnosis. These instruments are often bulky and intolerant
of field abuse, so designing compact, reliable, portable, and robust devices is a priority. In
contrast to most engineering designs, animals have been building compact and robust multichannel
imaging systems for millennia —their eyes. Biological sensors arise by evolution, of course, and are
not designed ‘for’ a particular use...
Source: Bioinspiration and Biomimetics - February 9, 2018 Category: Science Authors: Thomas W Cronin, Missael Garcia and Viktor Gruev Source Type: research
