scholarly journals Multi-Axial Hybrid Fire Testing based on Dynamic Relaxation

2021 ◽  
Author(s):  
Nikolaos Tsokanas ◽  
Giuseppe Abbiati ◽  
Konstantinos Kanellopoulos ◽  
Bozidar Stojadinovic
Keyword(s):  
Hybrid Model ◽  
Degrees Of Freedom ◽  
Experimental Validation ◽  
Technical Note ◽  
Static Response ◽  
Fire Testing ◽  
Dynamic Relaxation ◽  
Multiple Degrees Of Freedom ◽  
First Time

This technical note presents the experimental validation of a hybrid fire testing coordination algorithm recently developed by some of the authors. For the first time, the algorithm is applied to solve the static response of a multiple-degrees-of-freedom hybrid model.

scholarly journals On Differential Mechanisms for Underactuated, Lightweight, Adaptive Prosthetic Hands

2021 ◽  
Vol 15 ◽  
Author(s):  
Geng Gao ◽  
Mojtaba Shahmohammadi ◽  
Lucas Gerez ◽  
George Kontoudis ◽  
Minas Liarokapis
Keyword(s):  
Degrees Of Freedom ◽  
Experimental Validation ◽  
Minimal Set ◽  
Prosthetic Devices ◽  
Multiple Degrees Of Freedom ◽  
Prosthetic Hands ◽  
Promising Application ◽  
End Effectors ◽  
Critical Components ◽  
And Control

Over the last decade underactuated, adaptive robot grippers and hands have received an increased interest from the robotics research community. This class of robotic end-effectors can be used in many different fields and scenarios with a very promising application being the development of prosthetic devices. Their suitability for the development of such devices is attributed to the utilization of underactuation that provides increased functionality and dexterity with reduced weight, cost, and control complexity. The most critical components of underactuated, adaptive hands that allow them to perform a broad set of grasp poses are appropriate differential mechanisms that facilitate the actuation of multiple degrees of freedom using a single motor. In this work, we focus on the design, analysis, and experimental validation of a four output geared differential, a series elastic differential, and a whiffletree differential that can incorporate a series of manual and automated locking mechanisms. The locking mechanisms have been developed so as to enhance the control of the differential outputs, allowing for efficient grasp selection with a minimal set of actuators. The differential mechanisms are applied to prosthetic hands, comparing them and describing the benefits and the disadvantages of each.

scholarly journals Design, Fabrication, and Testing of a Novel 3D 3-Fingered Electrothermal Microgripper with Multiple Degrees of Freedom

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 444
Author(s):  
Guoning Si ◽  
Liangying Sun ◽  
Zhuo Zhang ◽  
Xuping Zhang
Keyword(s):  
Degrees Of Freedom ◽  
Dynamic Properties ◽  
Three Dimensional ◽  
Polyimide Film ◽  
Zebrafish Embryos ◽  
Multiple Degrees Of Freedom ◽  
Electrothermal Actuator ◽  
3D Space ◽  
Pick And Place

This paper presents the design, fabrication, and testing of a novel three-dimensional (3D) three-fingered electrothermal microgripper with multiple degrees of freedom (multi DOFs). Each finger of the microgripper is composed of a V-shaped electrothermal actuator providing one DOF, and a 3D U-shaped electrothermal actuator offering two DOFs in the plane perpendicular to the movement of the V-shaped actuator. As a result, each finger possesses 3D mobilities with three DOFs. Each beam of the actuators is heated externally with the polyimide film. The durability of the polyimide film is tested under different voltages. The static and dynamic properties of the finger are also tested. Experiments show that not only can the microgripper pick and place microobjects, such as micro balls and even highly deformable zebrafish embryos, but can also rotate them in 3D space.

scholarly journals The emerging technology of biohybrid micro-robots: a review

2021 ◽  
Author(s):  
Zening Lin ◽  
Tao Jiang ◽  
Jianzhong Shang
Keyword(s):  
Self Assembly ◽  
Degrees Of Freedom ◽  
High Energy ◽  
Living Cells ◽  
Multiple Degrees Of Freedom ◽  
The Past ◽  
Great Prevalence ◽  
Performance Decline ◽  
High Energy Efficiency ◽  
Living Tissues

Abstract In the past few decades, robotics research has witnessed an increasingly high interest in miniaturized, intelligent, and integrated robots. The imperative component of a robot is the actuator that determines its performance. Although traditional rigid drives such as motors and gas engines have shown great prevalence in most macroscale circumstances, the reduction of these drives to the millimeter or even lower scale results in a significant increase in manufacturing difficulty accompanied by a remarkable performance decline. Biohybrid robots driven by living cells can be a potential solution to overcome these drawbacks by benefiting from the intrinsic microscale self-assembly of living tissues and high energy efficiency, which, among other unprecedented properties, also feature flexibility, self-repair, and even multiple degrees of freedom. This paper systematically reviews the development of biohybrid robots. First, the development of biological flexible drivers is introduced while emphasizing on their advantages over traditional drivers. Second, up-to-date works regarding biohybrid robots are reviewed in detail from three aspects: biological driving sources, actuator materials, and structures with associated control methodologies. Finally, the potential future applications and major challenges of biohybrid robots are explored. Graphic abstract

scholarly journals Integrated structured light architectures

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Randy Lemons ◽  
Wei Liu ◽  
Josef C. Frisch ◽  
Alan Fry ◽  
Joseph Robinson ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Temporal Distribution ◽  
Multiple Degrees Of Freedom ◽  
Beam Combination ◽  
Angular Momenta ◽  
Field Control ◽  
Topological States ◽  
Spatio Temporal ◽  
Temporal Field ◽  
Structural Versatility

AbstractThe structural versatility of light underpins an outstanding collection of optical phenomena where both geometrical and topological states of light can dictate how matter will respond or display. Light possesses multiple degrees of freedom such as amplitude, and linear, spin angular, and orbital angular momenta, but the ability to adaptively engineer the spatio-temporal distribution of all these characteristics is primarily curtailed by technologies used to impose any desired structure to light. We demonstrate a laser architecture based on coherent beam combination offering integrated spatio-temporal field control and programmability, thereby presenting unique opportunities for generating light by design to exploit its topology.

scholarly journals Additive Manufacturing for Effective Smart Structures: The Idea of 6D Printing

2021 ◽  
Vol 5 (5) ◽  
pp. 119
Author(s):  
Stelios K. Georgantzinos ◽  
Georgios I. Giannopoulos ◽  
Panteleimon A. Bakalis
Keyword(s):  
Additive Manufacturing ◽  
Degrees Of Freedom ◽  
Smart Structures ◽  
Interaction Mechanism ◽  
Modeling And Simulations ◽  
Environmental Stimulus ◽  
Material Component ◽  
Design And Manufacturing ◽  
First Time ◽  
Printing Techniques

This paper aims to establish six-dimensional (6D) printing as a new branch of additive manufacturing investigating its benefits, advantages as well as possible limitations concerning the design and manufacturing of effective smart structures. The concept of 6D printing, to the authors’ best knowledge, is introduced for the first time. The new method combines the four-dimensional (4D) and five-dimensional (5D) printing techniques. This means that the printing process is going to use five degrees of freedom for creating the final object while the final produced material component will be a smart/intelligent one (i.e., will be capable of changing its shape or properties due to its interaction with an environmental stimulus). A 6D printed structure can be stronger and more effective than a corresponding 4D printed structure, can be manufactured using less material, can perform movements by being exposed to an external stimulus through an interaction mechanism, and it may learn how to reconfigure itself suitably, based on predictions via mathematical modeling and simulations.

scholarly journals Novel piezoelectric crawling robot with multiple degrees of freedom

AIP Advances ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 075306
Author(s):  
Ruikun Niu ◽  
Yu Guo
Keyword(s):  
Degrees Of Freedom ◽  
Multiple Degrees Of Freedom

scholarly journals BIOMIMETIC DESIGN OF LOW STIFFNESS ACTUATOR SYSTEMS FOR PROSTHETIC LIMBS

2011 ◽  
Author(s):  
D. L. Russell ◽  
M. McTavish
Keyword(s):  
Mechanical Properties ◽  
Degrees Of Freedom ◽  
Analytical Techniques ◽  
Energetic Costs ◽  
Multiple Degrees Of Freedom ◽  
Prosthetic Limbs ◽  
Limb Stiffness ◽  
Human Arm ◽  
Biomimetic Approach ◽  
Low Stiffness

The various relationships that are possible between the mechanical properties of single actuators and the overall mechanism (in this case a human arm with or without a prosthetic elbow) are discussed. Graphical and analytical techniques for describing the range of overall limb stiffnesses that are achievable and for characterizing the overall limb stiffness have been developed. Using a biomimetic approach and, considering energetic costs, stability and complexity, the implications of choosing passive or active implementations of stiffness are discussed. These techniques and approaches are particularly applicable with redundant (agonist - antagonist) actuators and multiple degrees of freedom. Finally, a novel biomimetic approach for control is proposed.

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