scholarly journals Additive Manufacturing for Soft Robotics: Design and Fabrication of Airtight, Monolithic Bending PneuNets with Embedded Air Connectors

Micromachines ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 485 ◽  
Author(s):  
Gianni Stano ◽  
Luca Arleo ◽  
Gianluca Percoco
Keyword(s):  
Additive Manufacturing ◽  
Wall Thickness ◽  
Chamber Wall ◽  
Soft Robotics ◽  
Soft Robot ◽  
Soft Robots ◽  
Bending Performance ◽  
3D Print ◽  
Air Tightness ◽  
The Relationship

Air tightness is a challenging task for 3D-printed components, especially for fused filament fabrication (FFF), due to inherent issues, related to the layer-by-layer fabrication method. On the other hand, the capability of 3D print airtight cavities with complex shapes is very attractive for several emerging research fields, such as soft robotics. The present paper proposes a repeatable methodology to 3D print airtight soft actuators with embedded air connectors. The FFF process has been optimized to manufacture monolithic bending PneuNets (MBPs), an emerging class of soft robots. FFF has several advantages in soft robot fabrication: (i) it is a fully automated process which does not require manual tasks as for molding, (ii) it is one of the most ubiquitous and inexpensive (FFF 3D printers costs < $200) 3D-printing technologies, and (iii) more materials can be used in the same printing cycle which allows embedding of several elements in the soft robot body. Using commercial soft filaments and a dual-extruder 3D printer, at first, a novel air connector which can be easily embedded in each soft robot, made via FFF technology with a single printing cycle, has been fabricated and tested. This new embedded air connector (EAC) prevents air leaks at the interface between pneumatic pipe and soft robot and replaces the commercial air connections, often origin of leakages in soft robots. A subsequent experimental study using four different shapes of MBPs, each equipped with EAC, showed the way in which different design configurations can affect bending performance. By focusing on the best performing shape, among the tested ones, the authors studied the relationship between bending performance and air tightness, proving how the Design for Additive Manufacturing approach is essential for advanced applications involving FFF. In particular, the relationship between chamber wall thickness and printing parameters has been analyzed, the thickness of the walls has been studied from 1.6 to 1 mm while maintaining air tightness and improving the bending angle by 76.7% under a pressure of 4 bar. It emerged that the main printing parameter affecting chamber wall air tightness is the line width that, in conjunction with the wall thickness, can ensure air tightness of the soft actuator body.

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>

Adaptive visual servoing control for an underwater soft robot

2018 ◽  
Vol 38 (5) ◽  
pp. 669-677 ◽  
Author(s):  
Fan Xu ◽  
Hesheng Wang ◽  
Weidong Chen ◽  
Jingchuan Wang
Keyword(s):  
System Dynamics ◽  
Visual Servoing ◽  
Soft Robotics ◽  
Soft Robot ◽  
Human Beings ◽  
Soft Robots ◽  
Content Type ◽  
Underwater Environment ◽  
Close Loop Control ◽  
Visual Servoing Control

PurposeSoft robotics, regarded as a new research branch of robotics, has generated increasing interests in this decade and has demonstrated its outperformance in addressing safety issues when cooperating with human beings. However, there is still lack of accurate close-loop control because of the difficulty in acquiring feedback information and accurately modeling the system, especially in interactive environments. To this end, this paper aims to improve the controllability of the soft robot working in specific underwater environment. The system dynamics, which takes complicated hydrodynamics into account, is solved using Kane’s method. The dynamics-based adaptive visual servoing controller is proposed to realize accurate sensorimotor control.Design/methodology/approachThis paper presents an image-based visual servoing control scheme for a cable-driven soft robot with a fixed camera observing the motions. The intrinsic and extrinsic parameters of the camera can be adapted online so that tedious camera calibration work can be eliminated. It is acknowledged that kinematics-based control can be only applied into tasks in the free space and has limitation in accelerating the motion speed of robot arms. That is, one must consider the unneglectable interaction effects generated from the environment and objectives when operating soft robots in such interactive control tasks. To extend the application of soft robots into underwater environment, the study models system dynamics considering complicated hydrodynamic effects. With the pre-knowledge of the external effects, the performance of the robot can be further improved by adding the compensation term into the controller.FindingsThe proposed controller has theoretically proved its convergence of image error, adaptive estimation error and the stability of the dynamical system based on Lyapunov’s analysis. The authors also validate the performance of the controller in positioning control task in an underwater environment. The controller shows its capacity of rapid convergence to and accurate tracking performance of a static image target in a physical experiment.Originality/valueTo the best of the authors’ knowledge, there is no such research before that has developed dynamics-based visual servoing controller which takes into account the environment interactions. This work can thus improve the control accuracy and enhance the applicability of soft robotics when operating in complicated environments.

scholarly journals The Sounds of Softness. Designing Sound for Human-Soft Robot Interaction

2021 ◽  
Vol 8 ◽  
Author(s):  
Jonas Jørgensen ◽  
Mads Bering Christiansen
Keyword(s):  
Design Process ◽  
Human Robot Interaction ◽  
Soft Robotics ◽  
Soft Robot ◽  
Robot Interaction ◽  
Soft Robots ◽  
Creative Practice ◽  
The Social ◽  
People’S Perception ◽  
The Aesthetic

In this article, we report on research and creative practice that explores the aesthetic interplay between movement and sound for soft robotics. Our inquiry seeks to interrogate what sound designs might be aesthetically engaging and appropriate for soft robotic movement in a social human-robot interaction setting. We present the design of a soft sound-producing robot, SONŌ, made of pliable and expandable silicone and three sound designs made for this robot. The article comprises an articulation of the underlying design process and results from two empirical interaction experiments (N = 66, N = 60) conducted to evaluate the sound designs. The sound designs did not have statistically significant effects on people’s perception of the social attributes of two different soft robots. Qualitative results, however, indicate that people’s interpretations of the sound designs depend on robot type.

scholarly journals Movement Detection in Soft Robotic Gripper Using Sinusoidally Embedded Fiber Optic Sensor

Sensors ◽  
2020 ◽  
Vol 20 (5) ◽  
pp. 1312 ◽  
Author(s):  
Mei Yang ◽  
Qidi Liu ◽  
Hamza Sayed Naqawe ◽  
Mable P. Fok
Keyword(s):  
Building Materials ◽  
Fiber Optic ◽  
External Perturbation ◽  
Fiber Optic Sensors ◽  
Fiber Optic Sensor ◽  
Soft Robotics ◽  
Soft Robot ◽  
Soft Robots ◽  
Optic Sensor ◽  
Novel Approach

Soft robotics is an emerging field, since it offers distinct opportunities in areas where conventional rigid robots are not a feasible solution. However, due to the complex motions of soft robots and the stretchable nature of soft building materials, conventional electronic and fiber optic sensors cannot be used in soft robots, thus, hindering the soft robots’ ability to sense and respond to their surroundings. Fiber Bragg grating (FBG)-based sensors are very popular among various fiber optic sensors, but their stiff nature makes it challenging to be used in soft robotics. In this study, a soft robotic gripper with a sinusoidally embedded stretchable FBG-based fiber optic sensor is demonstrated. Unlike a straight FBG embedding configuration, this unique sinusoidal configuration prevents sensor dislocation, supports stretchability and improves sensitivity by seven times when compared to a straight configuration. Furthermore, the sinusoidally embedded FBG facilitates the detection of various movements and events occurring at the soft robotic gripper, such as (de)actuation, object holding and external perturbation. The combination of a soft robot and stretchable fiber optic sensor is a novel approach to enable a soft robot to sense and response to its surroundings, as well as to provide its operation status to the controller.

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>

scholarly journals Advanced soft robot modeling in ChainQueen

Robotica ◽  
2021 ◽  
pp. 1-31
Author(s):  
Andrew Spielberg ◽  
Tao Du ◽  
Yuanming Hu ◽  
Daniela Rus ◽  
Wojciech Matusik
Keyword(s):  
Application Programming Interface ◽  
Material Point ◽  
Soft Robotics ◽  
Soft Robot ◽  
Inference Control ◽  
Simulation And Optimization ◽  
Efficient Simulation ◽  
Application Programming ◽  
Robot Modeling ◽  
Programming Interface

Abstract We present extensions to ChainQueen, an open source, fully differentiable material point method simulator for soft robotics. Previous work established ChainQueen as a powerful tool for inference, control, and co-design for soft robotics. We detail enhancements to ChainQueen, allowing for more efficient simulation and optimization and expressive co-optimization over material properties and geometric parameters. We package our simulator extensions in an easy-to-use, modular application programming interface (API) with predefined observation models, controllers, actuators, optimizers, and geometric processing tools, making it simple to prototype complex experiments in 50 lines or fewer. We demonstrate the power of our simulator extensions in over nine simulated experiments.

scholarly journals B-PO03-096 DIELECTRIC IMAGING ACCURATELY MEASURES REGIONAL CARDIAC CHAMBER WALL THICKNESS - AN IN VIVO STUDY

Heart Rhythm ◽  
2021 ◽  
Vol 18 (8) ◽  
pp. S227-S228
Author(s):  
Irum Kotadia ◽  
Iain Sim Michelle Williams ◽  
Caroline H. Roney ◽  
Jose Solis-Lemus ◽  
Orod Razeghi ◽  
...  
Keyword(s):  
Wall Thickness ◽  
Chamber Wall ◽  
In Vivo Study ◽  
Cardiac Chamber

scholarly journals Mechanics of the small punch test: a review and qualification of additive manufacturing materials

2021 ◽  
Vol 56 (18) ◽  
pp. 10707-10744
Author(s):  
Jonathan Torres ◽  
Ali P. Gordon
Keyword(s):  
Additive Manufacturing ◽  
Material Properties ◽  
Materials Science ◽  
Contemporary Literature ◽  
The Body ◽  
Small Punch Test ◽  
Small Punch ◽  
Punch Test ◽  
Testing Data ◽  
The Relationship

AbstractThe small punch test (SPT) was developed for situations where source material is scarce, costly or otherwise difficult to acquire, and has been used for assessing components with variable, location-dependent material properties. Although lacking standardization, the SPT has been employed to assess material properties and verified using traditional testing. Several methods exist for equating SPT results with traditional stress–strain data. There are, however, areas of weakness, such as fracture and fatigue approaches. This document outlines the history and methodologies of SPT, reviewing the body of contemporary literature and presenting relevant findings and formulations for correlating SPT results with conventional tests. Analysis of literature is extended to evaluating the suitability of the SPT for use with additively manufactured (AM) materials. The suitability of this approach is shown through a parametric study using an approximation of the SPT via FEA, varying material properties as would be seen with varying AM process parameters. Equations describing the relationship between SPT results and conventional testing data are presented. Correlation constants dictating these relationships are determined using an accumulation of data from the literature reviewed here, along with novel experimental data. This includes AM materials to assess the fit of these and provide context for a wider view of the methodology and its interest to materials science and additive manufacturing. A case is made for the continued development of the small punch test, identifying strengths and knowledge gaps, showing need for standardization of this simple yet highly versatile method for expediting studies of material properties and optimization.

659Left atrial wall thickness evaluation during atrial fibrillation redo procedures

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
C Teres ◽  
D Soto ◽  
B Jauregui ◽  
D Penela ◽  
A Ordonez ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Wall Thickness ◽  
Atrial Wall ◽  
Ablation Procedure ◽  
Left Atrial Wall ◽  
Local Distance ◽  
The Mean ◽  
The Right ◽  
The Relationship ◽  
Funding Acknowledgements

Abstract Funding Acknowledgements Dr Teres was funded by Swiss Heartrhythm Foundation Introduction pulmonary vein (PV) reconnections due to gaps on circumferential ablation lines are responsible for atrial fibrillation recurrences after catheter ablation. We sought to analyze the local left atrial wall thickness (LAWT) of PV line gaps at AF redo ablation during real-time catheter positioning. LAWT was measured on the MDCT 3D reconstruction and fused with the LA anatomy using CARTO-merge. Objective To analyze the relationship between local reconnection gaps and the LAWT during AF redo procedures. Methods Single-Center cohort study that included 41 consecutive patients referred for AF redo procedure. All patients had a MDCT prior to the ablation procedure. LAWT maps were semi-automatically computed from the MDCT as the local distance between the LA endo and epicardium. Each PV line was subdivided into 8 segments and mean LAWT was computed. During the procedure, the local gap was defined as the earliest activation site at the reconnected segment of the circumferential PV line (Figure 1A & 1B). Results 41 patients [31 (75.6%) male, age 60 ± 10 years] were included. Mean LAWT was 1.36 ± 0.20 mm. Mean PV circumferential line WT was higher in left PVs than in the right PVs 1.68 ± 0.57 vs. 1.31 ± 0.39 mm p &lt; 0.001 respectively. Mean WT of the reconnected points was 44% higher than the mean WT of the segment where the reconnection was located. Mean reconnection point WT was at the 87th percentile of the circumferential line in the LPVs and at the 76th percentile in the RPVs. The reconnected point WT was higher in the LPVs than RPVs 2.13 ± 1.14 vs. 1.47 ± 0.48 mm p &lt; 0.001 respectively.  The most frequent location for reconnections was the left anterior carina (71%), with a mean WT of 2.24 ± 0.91mm; and the right anterior carina (56%) with a mean WT of 1.57 ± 0.62mm (Figure 2A & 2B). Conclusions Reconnection points were more frequently present in the thicker segments of the PV circumferential line. The most frequently reconnected segment was the anterior carina in both right and left PVs. Atrial wall thickness maps derived from MDCT are useful to guide AF redo procedures. Abstract Figure. 1) Activation & WT map; 2) Segment WT

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