scholarly journals EuMoBot: replicating euglenoid movement in a soft robot

2018 ◽  
Vol 15 (148) ◽  
pp. 20180301 ◽  
Author(s):  
Krishna Manaswi Digumarti ◽  
Andrew T. Conn ◽  
Jonathan Rossiter
Keyword(s):  
Shape Change ◽  
Large Body ◽  
Small Mass ◽  
The Body ◽  
Soft Robot ◽  
Soft Robots ◽  
Characteristic Type ◽  
Viscous Forces ◽  
Wide Range ◽  
Euglenoid Movement

Swimming is employed as a form of locomotion by many organisms in nature across a wide range of scales. Varied strategies of shape change are employed to achieve fluidic propulsion at different scales due to changes in hydrodynamics. In the case of microorganisms, the small mass, low Reynolds number and dominance of viscous forces in the medium, requires a change in shape that is non-invariant under time reversal to achieve movement. The Euglena family of unicellular flagellates evolved a characteristic type of locomotion called euglenoid movement to overcome this challenge, wherein the body undergoes a giant change in shape. It is believed that these large deformations enable the organism to move through viscous fluids and tiny spaces. The ability to drastically change the shape of the body is particularly attractive in robots designed to move through constrained spaces and cluttered environments such as through the human body for invasive medical procedures or through collapsed rubble in search of survivors. Inspired by the euglenoids, we present the design of EuMoBot, a multi-segment soft robot that replicates large body deformations to achieve locomotion. Two robots have been fabricated at different sizes operating with a constant internal volume, which exploit hyperelasticity of fluid-filled elastomeric chambers to replicate the motion of euglenoids. The smaller robot moves at a speed of body lengths per cycle (20 mm min −1 or 2.2 cycles min −1 ) while the larger one attains a speed of body lengths per cycle (4.5 mm min −1 or 0.4 cycles min −1 ). We show the potential for biomimetic soft robots employing shape change to both replicate biological motion and act as a tool for studying it. In addition, we present a quantitative method based on elliptic Fourier descriptors to characterize and compare the shape of the robot with that of its biological counterpart. Our results show a similarity in shape of 85% and indicate that this method can be applied to understand the evolution of shape in other nonlinear, dynamic soft robots where a model for the shape does not exist.

The life cycle of Haplorchis pumilio (Trematoda: Heterophyidae) from the Indian region

2006 ◽  
Vol 80 (4) ◽  
pp. 327-332 ◽  
Author(s):  
K. Umadevi ◽  
R. Madhavi
Keyword(s):  
Life Cycle ◽  
Freshwater Fish ◽  
Large Body ◽  
The Body ◽  
Indian Region ◽  
Intermediate Hosts ◽  
Experimental Infections ◽  
Wide Range ◽  
Haplorchis Pumilio ◽  
Thiara Tuberculata

AbstractThe life cycle of the heterophyid fluke, Haplorchis pumilio is elucidated for the first time from the Indian region. Various stages in the life cycle were established based on observations made on natural infections found in snails and fish in a freshwater stream at Visakhapatnam, India and experimental infections carried out in the laboratory. The thiarid snail, Thiara tuberculata served as the first intermediate host and a wide range of freshwater fish as second intermediate hosts. Natural infections with adult flukes were found in the piscivorous birds Ardeola grayii and Bubulcus ibis. Adults were raised experimentally in day-old chicks. Distinguishing features of the cercaria of H. pumilio are: a large body size (200–224×92–96 μm), body–tail ratio of 1:2.1 and densely distributed pigment granules in the parenchyma imparting a brownish tinge to the body. Natural infections with metacercariae were found in the freshwater fish Channa punctatus, C. orientalis, Puntius sophore, Gambusia affinis and fingerlings of Cyprinus carpio and Liza macrolepis. Additionally, experimental infections were established in Therapon jarbua, Esomus danricus and Oreochromis mossambica. Metacercariae were embedded in the caudal muscles of fish and heavy infections induced mortality. Metacercariae were infective at about 15 days of age.

Feeding Behaviour of Three Species of Squirrels

Behaviour ◽  
1985 ◽  
Vol 95 (1-2) ◽  
pp. 76-86 ◽  
Author(s):  
Satoshi Shiraishi ◽  
Teru Aki Uchida ◽  
Motokazu Ando
Keyword(s):  
Feeding Behaviour ◽  
Large Body ◽  
The Body ◽  
Lateral Side ◽  
Experimental Conditions ◽  
Sitting Posture ◽  
Flying Squirrel ◽  
Interspecific Differences ◽  
Wide Range ◽  
Feeding Bout

AbstractThe Japanese giant flying squirrel, Petaurista leucogenys, Japanese flying squirrel, Pteromys momonga and Asiatic chipmunk, were compared for feeding behaviour under experimental conditions. Although P. leucogenys always fed in a sitting posture on branches, it extended its forepaws effectively both laterally and ventrally. When the animal was not able to place its large body on a slender twig, it brought the twig within reach of the mouth by the forepaws, obtaining food at the tip. P. momonga and T. s. asiaticus took a hanging posture, too, and the former was more skillful in this posture than was the latter. In picking up food scattered on the floor, P. leucogenys extended the body, without shifting its hindfeet, in a wide range including its lateral side; T. s. asiaticus got food in a narrow range only just in front of the body, and P. momonga had an intermediate range between those of the above two species. Among the three species, the daily frequency of feeding bouts was in inverse proportion to the duration of a feeding bout; P. leucogenys had relatively long and infrequent bouts, the reverse being the case with T. s. asiaticus. Characteristics of the posture, technique and frequency of feeding in the three species were supposed to be a reflection of interspecific differences in the diet, habitat, and freedom and length of the forelimb.

An untethered isoperimetric soft robot

2020 ◽  
Vol 5 (40) ◽  
pp. eaaz0492
Author(s):  
Nathan S. Usevitch ◽  
Zachary M. Hammond ◽  
Mac Schwager ◽  
Allison M. Okamura ◽  
Elliot W. Hawkes ◽  
...  
Keyword(s):  
Shape Change ◽  
External Source ◽  
Edge Length ◽  
Complex Structures ◽  
Soft Robot ◽  
Soft Robots ◽  
Form Complex ◽  
Human Scale ◽  
Real World Applications ◽  
Rolling Locomotion

For robots to be useful for real-world applications, they must be safe around humans, be adaptable to their environment, and operate in an untethered manner. Soft robots could potentially meet these requirements; however, existing soft robotic architectures are limited by their ability to scale to human sizes and operate at these scales without a tether to transmit power or pressurized air from an external source. Here, we report an untethered, inflated robotic truss, composed of thin-walled inflatable tubes, capable of shape change by continuously relocating its joints, while its total edge length remains constant. Specifically, a set of identical roller modules each pinch the tube to create an effective joint that separates two edges, and modules can be connected to form complex structures. Driving a roller module along a tube changes the overall shape, lengthening one edge and shortening another, while the total edge length and hence fluid volume remain constant. This isoperimetric behavior allows the robot to operate without compressing air or requiring a tether. Our concept brings together advantages from three distinct types of robots—soft, collective, and truss-based—while overcoming certain limitations of each. Our robots are robust and safe, like soft robots, but not limited by a tether; are modular, like collective robots, but not limited by complex subunits; and are shape-changing, like truss robots, but not limited by rigid linear actuators. We demonstrate two-dimensional (2D) robots capable of shape change and a human-scale 3D robot capable of punctuated rolling locomotion and manipulation, all constructed with the same modular rollers and operating without a tether.

OmniSkins: Robotic skins that turn inanimate objects into multifunctional robots

2018 ◽  
Vol 3 (22) ◽  
pp. eaat1853 ◽  
Author(s):  
Joran W. Booth ◽  
Dylan Shah ◽  
Jennifer C. Case ◽  
Edward L. White ◽  
Michelle C. Yuen ◽  
...  
Keyword(s):  
Natural World ◽  
Design Approach ◽  
Robot Design ◽  
Soft Robot ◽  
Two Dimensional ◽  
Soft Body ◽  
Soft Robots ◽  
Wide Range

Robots generally excel at specific tasks in structured environments but lack the versatility and the adaptability required to interact with and locomote within the natural world. To increase versatility in robot design, we present robotic skins that can wrap around arbitrary soft bodies to induce the desired motions and deformations. Robotic skins integrate actuation and sensing into a single conformable material and may be leveraged to create a multitude of controllable soft robots with different functions or gaits to accommodate the demands of different environments. We show that attaching the same robotic skin to a soft body in different ways, or to different soft bodies, leads to distinct motions. Further, we show that combining multiple robotic skins enables complex motions and functions. We demonstrate the versatility of this soft robot design approach in a wide range of applications—including manipulation tasks, locomotion, and wearables—using the same two-dimensional (2D) robotic skins reconfigured on the surface of various 3D soft, inanimate objects.

Rola tłuszczu w żywieniu człowieka

2019 ◽  
Vol 22 (4) ◽  
Author(s):  
Magdalena Rudzińska ◽  
Roman Przybylski
Keyword(s):  
Unsaturated Fatty Acids ◽  
Large Body ◽  
Calorific Value ◽  
Fats And Oils ◽  
Biological Properties ◽  
The Body ◽  
Dietary Fats ◽  
Human Diet ◽  
Wide Range

Along with proteins and carbohydrates, fat is one of the three most important components of the human diet. For years, it was recommended that the intake of fats should be as low as possible due to their high calorific value. It is currently assumed that 30-35% of dietary energy should come from fat as it is a source of many bioactive compounds, such as essential unsaturated fatty acids (EUFAs), antioxidants and vitamins (A, D, E, K), which must be delivered to the body with food. Their content in vegetable fats and oils varies greatly, and the existing consumer opinions and beliefs often contradict scientific knowledge. Currently, a large body of evidence supporting the important role of fats in the human diet may be found in literature. This paper discusses the basic components of vegetable fats and oils in terms of their chemical structure and biological properties. A wide range of dietary fats were reviewed for their fatty acid, tocopherol and sterol profiles. Based on these facts, criteria to be taken into account in the selection of dietary fats and food products were identified.

scholarly journals Light-steered locomotion of muscle-like hydrogel by self-coordinated shape change and friction modulation

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Qing Li Zhu ◽  
Cong Du ◽  
Yahao Dai ◽  
Matthias Daab ◽  
Marian Matejdes ◽  
...  
Keyword(s):  
Gold Nanoparticle ◽  
Shape Change ◽  
Light Irradiation ◽  
Soft Robot ◽  
Nanocomposite Hydrogel ◽  
Soft Robots ◽  
Hydrophobic Substrate ◽  
Anisotropic Structures ◽  
Light Stimuli

Abstract Many creatures have the ability to traverse challenging environments by using their active muscles with anisotropic structures as the motors in a highly coordinated fashion. However, most artificial robots require multiple independently activated actuators to achieve similar purposes. Here we report a hydrogel-based, biomimetic soft robot capable of multimodal locomotion fueled and steered by light irradiation. A muscle-like poly(N-isopropylacrylamide) nanocomposite hydrogel is prepared by electrical orientation of nanosheets and subsequent gelation. Patterned anisotropic hydrogels are fabricated by multi-step electrical orientation and photolithographic polymerization, affording programmed deformations. Under light irradiation, the gold-nanoparticle-incorporated hydrogels undergo concurrent fast isochoric deformation and rapid increase in friction against a hydrophobic substrate. Versatile motion gaits including crawling, walking, and turning with controllable directions are realized in the soft robots by dynamic synergy of localized shape-changing and friction manipulation under spatiotemporal light stimuli. The principle and strategy should merit designing of continuum soft robots with biomimetic mechanisms.

scholarly journals Fatness and thermoregulation of qualified rugby players

2019 ◽  
Vol 68 ◽  
pp. 02011
Author(s):  
Inese Pontaga ◽  
Jekaterina Liepina ◽  
Dzintra Kazoka ◽  
Silvija Umbrasko
Keyword(s):  
Body Mass ◽  
Body Fat ◽  
Large Body ◽  
The Body ◽  
Body Fat Percentage ◽  
Fat Percentage ◽  
Wide Range ◽  
The Mean ◽  
Body Fat Percent ◽  
Rugby Players

A large body size and mass are advantages in rugby. The desire to gain weight can bring players to become overweight or obese. This can worsen their thermoregulation and health risks. The aim was to evaluate anthropometric characteristics and to determine the effect of additional body fat percentage on sweat loss during play-match in male rugby players. Nineteen qualified male rugby players were tested during play-match. The age, height, body mass, body mass index (BMI) and body fat percent of participants were: 29 ± 6 years, 183 ± 7 cm, 96.86 ± 12.88 kg, 29.07 ± 3.90 kg/m2, 20.52 ± 5.64%, respectively. The skin fold thickness measurement was used to assess body fat percent. Body mass loss was detected by weighting. The mean BMI was 26.18 ± 2.37 (kg/m2) and the body fat 15.87 ± 3.97% in backs. Forwards were significantly heavier and had BMI 31.18 ± 3.44 (kg/m2)(p = 0.002) and the body fat 23.91 ± 4.02% (p < 0.001). The mean body mass decrease in the play-match was 1.83 ± 0.84%. The mean sweating intensity was 2.24 ± 1.07 l/h, but individual varied among players in very wide range (1.12–6.16 l/h). Relationships between the body fat percentage and sweating intensity was not determined (p > 0.05). Recommendation is to increase the volume of regular strength training, to correct the diet and liquid consumption.

A Quadruped Soft Robot for Climbing Parallel Rods

Robotica ◽  
2020 ◽  
pp. 1-13
Author(s):  
Nana Zhu ◽  
Hongbin Zang ◽  
Bing Liao ◽  
Huimin Qi ◽  
Zheng Yang ◽  
...  
Keyword(s):  
Body Length ◽  
High Voltage ◽  
Control Strategy ◽  
The Body ◽  
Maximum Speed ◽  
Soft Robot ◽  
Climbing Robot ◽  
Soft Robots ◽  
Bending Actuator ◽  
Moving Speed

SUMMARY Soft robots can perform effectively inspecting than rigid robots in some special environments such as nuclear pipelines and high-voltage cables. This article presents a versatile quadruped soft rod-climbing robot (SR-CR) that consists of four bending actuators and a telescopic actuator. The bending actuator is composed of flexible bellows with multiple folding air chambers, elastic telescopic layer (ETL), and strain-limiting layer (SLL). The telescopic actuator provides the energy for the robot to climb forward. The SR-CR is activated by a control strategy that alternates the body deformation and feet pneumatic clenched for stable climbing. The robot can climb rods at 90°, with the maximum speed of up to 2.33 mm/s (0.018 body length/s). At 0.83 HZ, the maximum moving speed of the robot in climbing horizontally parallel rods can reach 18.43 mm/s. In addition, the SR-CR can also achieve multiple impressive functions, including turning around a corner at a rate of 7 mm/s (0.054 body length/s), carrying a payload of 3.7 times its self-weight on horizontal rods at a speed of 9 mm/s (0.069 body length/s).

Microstructural characterization of laser-melted/roller-quenched dicalcium silicate

1988 ◽  
Vol 46 ◽  
pp. 582-583
Author(s):  
C. J. Chan ◽  
K. R. Venkatachari ◽  
W. M. Kriven ◽  
J. F. Young
Keyword(s):  
Particle Size ◽  
Raw Materials ◽  
Shape Change ◽  
Microstructural Characterization ◽  
Particle Size Effect ◽  
Dicalcium Silicate ◽  
Laser Melting ◽  
Uniform Size ◽  
Cell Shape Change ◽  
Wide Range

Dicalcium silicate (Ca2SiO4) is a major component of Portland cement. It has also been investigated as a potential transformation toughener alternative to zirconia. It has five polymorphs: α, α'H, α'L, β and γ. Of interest is the β-to-γ transformation on cooling at about 490°C. This transformation, accompanied by a 12% volume increase and a 4.6° unit cell shape change, is analogous to the tetragonal-to-monoclinic transformation in zirconia. Due to the processing methods used, previous studies into the particle size effect were limited by a wide range of particle size distribution. In an attempt to obtain a more uniform size, a fast quench rate involving a laser-melting/roller-quenching technique was investigated.The laser-melting/roller-quenching experiment used precompacted bars of stoichiometric γ-Ca2SiO4 powder, which were synthesized from AR grade CaCO3 and SiO2xH2O. The raw materials were mixed by conventional ceramic processing techniques, and sintered at 1450°C. The dusted γ-Ca2SiO4 powder was uniaxially pressed into 0.4 cm x 0.4 cm x 4 cm bars under 34 MPa and cold isostatically pressed under 172 MPa. The γ-Ca2SiO4 bars were melted by a 10 KW-CO2 laser.

Creating the Wind

2020 ◽  
Vol 2 (4) ◽  
pp. 14-31
Author(s):  
Élodie Dupey García
Keyword(s):  
Indigenous Communities ◽  
The Body ◽  
Historical Sources ◽  
Natural Behavior ◽  
Sensory Experiences ◽  
Identity And Agency ◽  
Wide Range ◽  
Late Postclassic ◽  
Comparative Examination ◽  
Meteorological Phenomenon

This article explores how the Nahua of late Postclassic Mesoamerica (1200–1521 CE) created living and material embodiments of their wind god constructed on the basis of sensory experiences that shaped their conception of this divinized meteorological phenomenon. In this process, they employed chromatic and design devices, based on a wide range of natural elements, to add several layers of meaning to the human, painted, and sculpted supports dressed in the god’s insignia. Through a comparative examination of pre-Columbian visual production—especially codices and sculptures—historical sources mainly written in Nahuatl during the viceregal period, and ethnographic data on indigenous communities in modern Mexico, my analysis targets the body paint and shell jewelry of the anthropomorphic “images” of the wind god, along with the Feathered Serpent and the monkey-inspired embodiments of the deity. This study identifies the centrality of other human senses beyond sight in the conception of the wind god and the making of its earthly manifestations. Constructing these deity “images” was tantamount to creating the wind because they were intended to be visual replicas of the wind’s natural behavior. At the same time, they referred to the identity and agency of the wind god in myths and rituals.

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