scholarly journals Strategies to Control Performance of 3D-Printed, Cable-Driven Soft Polymer Actuators: From Simple Architectures to Gripper Prototype

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 846 ◽  
Author(s):  
Viacheslav Slesarenko ◽  
Seiji Engelkemier ◽  
Pavel Galich ◽  
Dmitry Vladimirsky ◽  
Gregory Klein ◽  
...  
Keyword(s):  
Mechanical Response ◽  
Weight Lifting ◽  
Polymer Actuators ◽  
Cable Channel ◽  
Polymer Actuator ◽  
3D Printed ◽  
Soft Polymer ◽  
Soft Actuators ◽  
Design And Manufacture ◽  
Selection Of

The following is a study of the performance of soft cable-driven polymer actuators produced by multimaterial 3D printing. We demonstrate that the mechanical response of the polymer actuator with an embedded cable can be flexibly tuned through the targeted selection of actuator architecture. Various strategies, such as the addition of discrete or periodic stiff inserts, the sectioning of the actuator, or the shifting of the cable channel are employed to demonstrate ways to achieve more controllable deformed shape during weight lifting or reduce the required actuation force. To illustrate these concepts, we design and manufacture a prototype of the soft polymer gripper, which is capable of manipulating small, delicate objects. The explored strategies can be utilized in other types of soft actuators, employing, for instance, actuation by means of electroactive polymers.

Electromechanical characterization of magnetic responsive and conductive soft polymer actuators

2020 ◽  
pp. 349-361 ◽  
Author(s):  
A.W. Gan ◽  
Kirthika Senthil Kumar ◽  
Lei Zhang ◽  
Jianyong Ouyang ◽  
Hongliang Ren
Keyword(s):  
Polymer Actuators ◽  
Soft Polymer ◽  
Electromechanical Characterization

scholarly journals 3D Printing of Thermo-Sensitive Drugs

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1524
Author(s):  
Sadikalmahdi Abdella ◽  
Souha H. Youssef ◽  
Franklin Afinjuomo ◽  
Yunmei Song ◽  
Paris Fouladian ◽  
...  
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Fused Deposition Modelling ◽  
Future Directions ◽  
Digital Light Processing ◽  
Fused Deposition ◽  
Printing Technique ◽  
3D Printed ◽  
Semi Solid ◽  
Selection Of

Three-dimensional (3D) printing is among the rapidly evolving technologies with applications in many sectors. The pharmaceutical industry is no exception, and the approval of the first 3D-printed tablet (Spiratam®) marked a revolution in the field. Several studies reported the fabrication of different dosage forms using a range of 3D printing techniques. Thermosensitive drugs compose a considerable segment of available medications in the market requiring strict temperature control during processing to ensure their efficacy and safety. Heating involved in some of the 3D printing technologies raises concerns regarding the feasibility of the techniques for printing thermolabile drugs. Studies reported that semi-solid extrusion (SSE) is the commonly used printing technique to fabricate thermosensitive drugs. Digital light processing (DLP), binder jetting (BJ), and stereolithography (SLA) can also be used for the fabrication of thermosensitive drugs as they do not involve heating elements. Nonetheless, degradation of some drugs by light source used in the techniques was reported. Interestingly, fused deposition modelling (FDM) coupled with filling techniques offered protection against thermal degradation. Concepts such as selection of low melting point polymers, adjustment of printing parameters, and coupling of more than one printing technique were exploited in printing thermosensitive drugs. This systematic review presents challenges, 3DP procedures, and future directions of 3D printing of thermo-sensitive formulations.

scholarly journals INFLUENCE OF PRINTING AND LOADING DIRECTION ON MECHANICAL RESPONSE IN 3D PRINTED MODELS OF HUMAN TRABECULAR BONE

2018 ◽  
Vol 18 ◽  
pp. 24 ◽  
Author(s):  
Tomáš Doktor ◽  
Ivana Kumpová ◽  
Sebastian Wroński ◽  
Maciej Śniechowski ◽  
Jacek Tarasiuk ◽  
...  
Keyword(s):  
Trabecular Bone ◽  
Mechanical Response ◽  
Plastic Region ◽  
Human Donor ◽  
Deformation Response ◽  
Human Trabecular Bone ◽  
Loading Mode ◽  
Loading Direction ◽  
3D Printed ◽  
X Ray Computed

The paper deals with investigation on directional variations of mechanical response in 3D printed models of human trabecular bone. Sample of trabecular bone tissue was resected from human donor and 3D model was obtained by X-ray computed tomography. Then a series of cubical samples was prepared by additive manufacturing technique and tested by uniaxial compression loading mode. Mechanical response was compared in nine different combinations of direction of 3D printing and loading direction. The results show neglectible influence on the deformation response in elastic region (stiffness) and significant changes of the behaviour in plastic region (stress and strain at yield point, strain at full collapse).

3-D Printing of Dielectric Electroactive Polymer Actuators and Characterization of Dielectric Flexible Materials

2018 ◽  
Author(s):  
David Gonzalez ◽  
Brittany Newell ◽  
Jose Garcia ◽  
Lucas Noble ◽  
Trevor Mamer
Keyword(s):  
Dielectric Material ◽  
Electrical Stimulus ◽  
Electroactive Polymer ◽  
Stress Strain ◽  
Active Structure ◽  
Flexible Material ◽  
Polymer Actuator ◽  
3D Printed ◽  
High Dielectric ◽  
Area Expansion

Dielectric electroactive polymers are materials capable of mechanically adjusting their volume in response to an electrical stimulus. However, currently these materials require multi-step manufacturing processes which are not additive. This paper presents a novel 3D printed flexible dielectric material and characterizes its use as a dielectric electroactive polymer (DEAP) actuator. The 3D printed material was characterized electrically and mechanically and its functionality as a dielectric electroactive polymer actuator was demonstrated. The flexible 3-D printed material demonstrated a high dielectric constant and ideal stress-strain performance in tensile testing making the 3-D printed material ideal for use as a DEAP actuator. The tensile stress-strain properties were measured on samples printed under three different conditions (three printing angles 0°, 45° and 90°). The results demonstrated the flexible material presents different responses depending on the printing angle. Based on these results, it was possible to determine that the active structure needs low pre-strain to perform a visible contractive displacement when voltage is applied to the electrodes. The actuator produced an area expansion of 5.48% in response to a 4.3 kV applied voltage, with an initial pre-strain of 63.21% applied to the dielectric material.

Investigation of infill-patterns on mechanical response of 3D printed poly-lactic-acid

2020 ◽  
Vol 87 ◽  
pp. 106557 ◽  
Author(s):  
Bandar Aloyaydi ◽  
Subbarayan Sivasankaran ◽  
Ammar Mustafa
Keyword(s):  
Lactic Acid ◽  
Mechanical Response ◽  
Poly Lactic Acid ◽  
3D Printed

3D Printed Composites With Continuous Carbon Fiber Reinforcements

2017 ◽  
Author(s):  
Ali N. Sarvestani ◽  
Nekoda van de Werken ◽  
Pouria Khanbolouki ◽  
Mehran Tehrani
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
High Performance ◽  
Mechanical Response ◽  
Failure Mechanisms ◽  
Micro Structure ◽  
Design Rules ◽  
Continuous Carbon Fiber ◽  
Fiber Reinforcements ◽  
3D Printed

Additively manufactured polymers can be reinforced with high-performance reinforcements such as carbon fibers. Printed thermoplastics with embedded continuous carbon fibers are up to two orders of magnitude stronger and stiffer than high-grade 3D printed polymers. In this work, the mechanical response of such 3D printed carbon fiber specimens is evaluated. While the precursor carbon fiber reinforced filaments achieve a stiffness of 50GPa and strength 700MPa, mechanical properties of their printed parts are highly affected by printed carbon fiber curvatures. In this work, the structure of 3D printed parts was examined, and some design rules for 3D printing with continuous carbon fibers are suggested. Moreover, failure mechanisms in these samples are discussed and correlated to the micro-structure of the composites and the carbon fiber configuration.

Structure, Process, and Material Influences for 3D Printed Lattices Designed With Mixed Unit Cells

2020 ◽  
Author(s):  
Gabriel Briguiet ◽  
Paul F. Egan
Keyword(s):  
Elastic Modulus ◽  
Mechanical Testing ◽  
Mechanical Response ◽  
Cell Types ◽  
Unit Cell ◽  
Ultraviolet Curing ◽  
Mechanical Responses ◽  
Lattice Design ◽  
Unit Cells ◽  
3D Printed

Abstract Emerging 3D printing technologies are enabling the design and fabrication of novel architected structures with advantageous mechanical responses. Designing complex structures, such as lattices, with a targeted response is challenging because build materials, fabrication process, and topological design have unique influences on the structure’s mechanical response. Changing any factor may have unanticipated consequences, even for simpler lattice structures. Here, we conduct mechanical compression experiments to investigate varied lattice design, fabrication, and material combinations using stereolithography printing with a biocompatible polymer. Mechanical testing demonstrates that a higher ultraviolet curing time increases elastic modulus. Material testing demonstrated that anisotropy does not strongly influence lattice mechanics. Designs were altered by comparing homogenous lattices of single unit cell types and heterogeneous lattices that combine two types of unit cells. Unit cells for heterogeneous structures include a Cube design for a high elastic modulus and Cross design for improved shear response. Mechanical testing of three heterogeneous layouts demonstrated how unit cell organization influences mechanical outcomes, therefore enabling the tuning of an elastic modulus that surpasses the law of averages designed for application-dependent mechanical needs. These findings provide a foundation for linking design, process, and material for engineering 3D printed structures with preferred properties, while also facilitating new directions in design automation and optimization.

Design of a Deformable Smart Tire Using Soft Actuator

2019 ◽  
Author(s):  
Vidya K. Nandikolla ◽  
Michael Costa ◽  
Nathan Boyd ◽  
Gilberto Rosales
Keyword(s):  
Force Feedback ◽  
Design Procedure ◽  
Nickel Titanium ◽  
Operating Conditions ◽  
Mechanical Modeling ◽  
Soft Actuator ◽  
Voltage Signal ◽  
3D Printed ◽  
Primary Focus ◽  
Soft Actuators

Abstract The unique functional properties of nickel-titanium Shape Memory Alloys (SMA) enable them to be used as actuators. This research paper demonstrates theoretically and experimentally the feasibility of using SMA in smart tires for a mobile robot. The design procedure for SMA as a coil spring actuator for a soft deformable wheel is described. The primary focus is the mechanical modeling, manufacturing, and system dynamics of a soft deformable wheel. The 3D printed soft tire exploits the capabilities of the SMA actuation using a voltage signal. The printed components are activated and integrated with electromechanical circuit for wireless communication system. The performance of the force feedback control system is evaluated at different operating conditions to demonstrate the shape-changing characteristic of the smart tire. The developed prototype is designed to propel forward and backward on flat and uneven surface. The experimental results obtained demonstrate the potential of SMA as soft actuators, its benefits and limitations as flexible systems.

scholarly journals Control-Oriented Modelling of a 3D-Printed Soft Actuator

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 71 ◽  
Author(s):  
Ali Zolfagharian ◽  
Akif Kaynak ◽  
Sui Yang Khoo ◽  
Jun Zhang ◽  
Saeid Nahavandi ◽  
...  
Keyword(s):  
3D Printing ◽  
Dynamic Models ◽  
Three Dimensional ◽  
Input Voltage ◽  
Soft Actuator ◽  
Voltage Variation ◽  
Sophisticated Model ◽  
3D Printed ◽  
Rc Circuit ◽  
Soft Actuators

A new type of soft actuator was developed by using hydrogel materials and three-dimensional (3D) printing technology, attracting the attention of researchers in the soft robotics field. Due to parametric uncertainties of such actuators, which originate in both a custom design nature of 3D printing as well as time and voltage variant characteristics of polyelectrolyte actuators, a sophisticated model to estimate their behaviour is required. This paper presents a practical modeling approach for the deflection of a 3D printed soft actuator. The suggested model is composed of electrical and mechanical dynamic models while the earlier version describes the actuator as a resistive-capacitive (RC) circuit. The latter model relates the ionic charges to the bending of an actuator. The experimental results were acquired to estimate the transfer function parameters of the developed model incorporating Takagi-Sugeno (T-S) fuzzy sets. The proposed model was successful in estimating the end-point trajectory of the actuator, especially in response to a broad range of input voltage variation. With some modifications in the electromechanical aspects of the model, the proposed modelling method can be used with other 3D printed soft actuators.

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