Heads or Tails? Cranio-Caudal Mass Distribution for Robust Locomotion with Biorobotic Appendages Composed of 3D-Printed Soft Materials

2019 ◽  
pp. 240-253
Author(s):  
Robert Siddall ◽  
Fabian Schwab ◽  
Jenny Michel ◽  
James Weaver ◽  
Ardian Jusufi
Keyword(s):  
Mass Distribution ◽  
Soft Materials ◽  
3D Printed

Effects of geometry and mass distribution in 3D printed metastructures for vibration mitigation

2019 ◽  
Vol 145 (3) ◽  
pp. 1760-1761
Author(s):  
Ignacio Arretche ◽  
Ganesh U. Patil ◽  
Kathryn H. Matlack
Keyword(s):  
Mass Distribution ◽  
Vibration Mitigation ◽  
3D Printed

Mechanical Properties of 3D Printed Biomimicked Composites

2018 ◽  
Author(s):  
Seyed M. Allameh ◽  
Roger Miller ◽  
Hadi Allameh
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Soft Materials ◽  
Structural Composites ◽  
Home Building ◽  
Complex Shapes ◽  
3D Printed ◽  
Bend Tests ◽  
Point Bend

Additive manufacturing technology has significantly matured over the last two decades. Recent progress in 3D printing has made it an attractive choice for fabricating complex shapes out of select materials possessing desirable properties at small and large scales. The application of biomimetics to the fabrication of structural composites has been shown to enhance their toughness and dynamic shear resistance. Building homes from bioinspired composites is possible if the process is automated. This can be achieved through additive manufacturing where layers of hard and soft materials can be deposited by 3D printing. This study examines mechanical properties of reinforced concrete fabricated by 3D printing. Preliminary results of 4-point bend tests are presented and the implications of 3D-printed home building on current conventional construction practices are discussed.

scholarly journals Well, Actuate(ly)...: Parametric Multi-Material 3D Printed Soft Robotics

2021 ◽  
Author(s):  
Patrick Coulson
Keyword(s):  
Complex Geometry ◽  
Casting Process ◽  
Soft Materials ◽  
Research Field ◽  
Soft Robotics ◽  
Soft Robots ◽  
3D Print ◽  
Parametric Control ◽  
3D Printed ◽  
Polyjet Printing

<b>In recent years, soft robotics has gained wide interest in the research field and has also garnered some commercial success. This is because soft robots are comprised of soft materials that have inherent compliance which lends them to a wide variety of applications that are not suited to traditional hard-bodied robots. </b><p>Soft robots are generally created using a casting process, which comes with limitations to the geometry due to the removal of the cast body from the mould. This research seeks to enhance the capabilities of soft robotic limbs using multi-material Polyjet printing – a recently developed additive manufacturing technology – which allows for geometric freedom and variable materials within a singular soft 3D print which is not feasible using other fabrication methods. </p> <p>This research draws inspiration from natural mechanisms such as muscular hydrostats, to enable the exploration of singular channel soft robots that exhibit bending, twisting, elongation, and expansion all in one 3D print. The geometric freedom and variable materiality of the Stratasys J750 produce actuation results for each motion that cannot be easily replicated using traditional fabrication techniques. The printable materials of the Stratasys J750 were found to have tendencies to tear upon inflation, however, a large array of prints with complex geometry were able to successfully actuate despite this. In some areas, results outperformed actuators made using other fabrication techniques, as was particularly evident in the twisting actuators. Through fine-tuned parametric control with equation-driven modelling, this portfolio presents a method for soft robotic design and construction that can produce a limb with multiple motions and up to 5 axes of movement that can be tailored to specific pre-defined applications.</p>

A Three-Dimensional Printed, Nonassembly, Passive Dynamic Walking Toy: Design and Analysis

2018 ◽  
Vol 10 (6) ◽  
Author(s):  
Christian L. Treviño ◽  
Joseph D. Galloway ◽  
Pranav A. Bhounsule
Keyword(s):  
3D Printing ◽  
Mass Distribution ◽  
Three Dimensional ◽  
Mass Distributions ◽  
Wide Range ◽  
Walking Motion ◽  
Wood Carving ◽  
3D Printed ◽  
Kinematic Mechanisms ◽  
Toy Design

In this paper, we present the redesign and analysis of a century old walking toy. Historically, the toy is made up of two wooden pieces including a rear leg and a front leg and body (as a single piece) that are attached to each other by means of a pin joint. When the toy is placed on a ramp and given a slight perturbation, it ambles downhill powered only by gravity. Before the toy can walk successfully, it needs careful tuning of its geometry and mass distribution. The traditional technique of manual wood carving offers very limited flexibility to tune the mass distribution and geometry. We have re-engineered the toy to be three-dimensional (3D) printed as a single integrated assembly that includes a pin joint and the two legs. After 3D printing, we have to manually break-off the weakly held support material to allow movement of the pin joint. It took us 6 iterations to progressively tune the leg geometry, mass distribution, and hinge joint tolerances to create our most successful working prototype. The final 3D printed toy needs minimal postprocessing and walks reliably on a 7.87 deg downhill ramp. Next, we created a computer model of the toy to explain its motion and stability. Parameter studies reveal that the toy exhibits stable walking motion for a fairly wide range of mass distributions. Although 3D printing has been used to create nonassembly articulated kinematic mechanisms, this is the first study that shows that it is possible to create dynamics-based nonassembly mechanisms such as walking toys.

scholarly journals 3D Printed Biomimetic Rabbit Airway Simulation Model for Nasotracheal Intubation Training

2020 ◽  
Vol 7 ◽  
Author(s):  
Gunpreet Oberoi ◽  
M. C. Eberspächer-Schweda ◽  
Sepideh Hatamikia ◽  
Markus Königshofer ◽  
Doris Baumgartner ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Nasotracheal Intubation ◽  
Soft Materials ◽  
Tactile Feedback ◽  
Material Behavior ◽  
Imaging Data ◽  
Micro Computed Tomography ◽  
Inhalation Anesthesia ◽  
Significant Difference ◽  
3D Printed

Rabbit inhalation anesthesia by endotracheal intubation involves a higher risk among small animals owing to several anatomical and physiological features, which is pathognomonic to this species of lagomorphs. Rabbit-specific airway devices have been designed to prevent misguided intubation attempts. However, it is believed that expert anesthetic training could be a boon in limiting the aftermaths of this procedure. Our research is aimed to develop a novel biomimetic 3D printed rabbit airway model with representative biomechanical material behavior and radiodensity. Imaging data were collected for two sacrificed rabbit heads using micro-computed tomography (μCT) and micro-magnetic resonance imaging for the first head and cone beam computed tomography (CBCT) for the second head. Imaging-based life-size musculoskeletal airway models were printed using polyjet technology with a combination of hard and soft materials in replicates of three. The models were evaluated quantitatively for dimensional accuracy and radiodensity and qualitatively using digital microscopy and endoscopy for technical, tactic, and visual realism. The results displayed that simulation models printed with polyjet technology have an overall surface representation of 93% for μCT-based images and 97% for CBCT-based images within a range of 0.0–2.5 mm, with μCT showing a more detailed reproduction of the nasotracheal anatomy. Dimensional discrepancies can be caused due to inadequate support material removal and due to the limited reconstruction of microstructures from the imaging on the 3D printed model. The model showed a significant difference in radiodensities in hard and soft tissue regions. Endoscopic evaluation provided good visual and tactile feedback, comparable to the real animal. Overall, the model, being a practical low-cost simulator, comprehensively accelerates the learning curve of veterinary nasotracheal intubation and paves the way for 3D simulation-based image-guided interventional procedures.

A Miniature, 3D-Printed, Walking Robot With Soft Joints

2017 ◽  
Author(s):  
Anthony DeMario ◽  
Jianguo Zhao
Keyword(s):  
3D Printing ◽  
Numerical Method ◽  
Body Length ◽  
Soft Materials ◽  
Search And Rescue ◽  
Walking Robot ◽  
Miniature Robots ◽  
Revolute Joints ◽  
3D Printed ◽  
Locomotion Speed

Miniature robots have many applications ranging from military surveillance to search and rescue in disaster areas. Nevertheless, the fabrication of such robots has traditionally been labor-intensive and time-consuming. This paper proposes to directly leverage multi-material 3D printing (MM3P) to fabricate centimeter-scale robots by utilizing soft materials to create soft joints in replacement of revolute joints. We demonstrate the capability of MM3P by creating a miniature, four-legged walking robot. Moreover, we establish a numerical method based on the Psuedorigid-Body (PRB) 1R model to predict the motion of the leg mechanism with multiple soft joints. Experimental results verify the proposed numerical method. Meanwhile, a functional walking robot actuated by a single DC motor is demonstrated with a locomotion speed of one body length/sec. The proposed design, fabrication, and analysis for the walking robot can be readily applied to other robots that have mechanisms with soft joints.

Recent Developments in Bio-Inspired Sensors Fabricated by Additive Manufacturing Technologies

2016 ◽  
Vol 100 ◽  
pp. 197-206 ◽  
Author(s):  
Gijs J.M. Krijnen ◽  
Remco G.P. Sanders
Keyword(s):  
Additive Manufacturing ◽  
Soft Materials ◽  
Main Stream ◽  
Micro Fabrication ◽  
Great Progress ◽  
Recent Developments ◽  
3D Printed ◽  
Manufacturing Technologies ◽  
Hair Sensors ◽  
Initial Results

In our work on micro-fabricated hair-sensors, inspired by the flow-sensitive sensors found on crickets, we have made great progress. Initially delivering mediocre performance compared to their natural counter parts they have evolved into capable sensors with thresholds roughly a factor of 30 larger than of their natural equivalents. Due to this disparity, and also instigated by our work on fly-halteres inspired rotation rate sensors and desert locust ear-drum mimicking membrane struc- tures, we have analysed the differences in performance between natural and man-made sensors. We conclude that two major drawbacks of main-stream micro-fabrication are the lack of easily applicable soft materials, as well as the limitations imposed by photolithography based fabrication with respect to freeform 3D shaping of structures. Currently we are targeting additive manufacturing for biomimetic sensor structures and in this contribution we report initial results of 3D printed sensor structures.

scholarly journals Predicting precision grip grasp locations on three-dimensional objects

2018 ◽  
Author(s):  
Lina K. Klein ◽  
Guido Maiello ◽  
Vivian C. Paulun ◽  
Roland W. Fleming
Keyword(s):  
Mass Distribution ◽  
Precision Grip ◽  
Three Dimensional ◽  
Behavioral Data ◽  
Three Dimensional Objects ◽  
3D Objects ◽  
Contact Points ◽  
Potential Contact ◽  
3D Printed ◽  
Precision Grasping

AbstractWe rarely experience difficulty picking up objects, yet of all potential contact points on the surface, only a small proportion yield effective grasps. Here, we present extensive behavioral data alongside a normative model that correctly predicts human precision grasping of unfamiliar 3D objects. We tracked participants’ forefinger and thumb as they picked up objects of 10 wood and brass cubes configured to tease apart effects of shape, weight, orientation, and mass distribution. Grasps were highly systematic and consistent across repetitions and participants. We employed these data to construct a model which combines five cost functions related to force closure, torque, natural grasp axis, grasp aperture, and visibility. Even without free parameters, the model predicts individual grasps almost as well as different individuals predict one another’s, but fitting weights reveals the relative importance of the different constraints. The model also accurately predicts human grasps on novel 3D-printed objects with more naturalistic geometries and is robust to perturbations in its key parameters. Together, the findings provide a unified account of how we successfully grasp objects of different 3D shape, orientation, mass, and mass distribution.Author SummaryA model based on extensive behavioral data unifies the varied and fragmented literature on human grasp selection by correctly predicting human grasps across a wide variety of conditions.

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