scholarly journals A soft matter computer for soft robots

2019 ◽  
Vol 4 (33) ◽  
pp. eaaw6060 ◽  
Author(s):  
M. Garrad ◽  
G. Soter ◽  
A. T. Conn ◽  
H. Hauser ◽  
J. Rossiter
Keyword(s):  
Smart Materials ◽  
Soft Matter ◽  
Autonomous Robots ◽  
Low Cost ◽  
Input Parameter ◽  
Soft Materials ◽  
Soft Robots ◽  
Stimulus Response ◽  
Bending Actuator ◽  
Two Degree Of Freedom

Despite the growing interest in soft robotics, little attention has been paid to the development of soft matter computational mechanisms. Embedding computation directly into soft materials is not only necessary for the next generation of fully soft robots but also for smart materials to move beyond stimulus-response relationships and toward the intelligent behaviors seen in biological systems. This article describes soft matter computers (SMCs), low-cost, and easily fabricated computational mechanisms for soft robots. The building block of an SMC is a conductive fluid receptor (CFR), which maps a fluidic input signal to an electrical output signal via electrodes embedded into a soft tube. SMCs could perform both analog and digital computation. The potential of SMCs is demonstrated by integrating them into three soft robots: (i) a Softworm robot was controlled by an SMC that generated the control signals necessary for three distinct gaits; (ii) a soft gripper was given a set of reflexes that could be programmed by adjusting the parameters of the CFR; and (iii) a two–degree of freedom bending actuator was switched between three distinct behaviors by varying only one input parameter. SMCs are a low-cost way to integrate computation directly into soft materials and an important step toward entirely soft autonomous robots.

VISUALIZING SOFT MATTER: MESOSCOPIC SIMULATIONS OF MEMBRANES, VESICLES AND NANOPARTICLES

2007 ◽  
Vol 02 (01) ◽  
pp. 33-55 ◽  
Author(s):  
JULIAN SHILLCOCK ◽  
REINHARD LIPOWSKY
Keyword(s):  
Smart Materials ◽  
Soft Matter ◽  
Dissipative Particle Dynamics ◽  
Lipid Vesicles ◽  
Soft Materials ◽  
Coarse Grained ◽  
Molecular Characteristics ◽  
Dynamics Simulations ◽  
And Behavior ◽  
Mesoscopic Simulations

Biological membranes have properties and behavior that emerge from the propagation of the molecular characteristics of their components across many scales. Artificial smart materials, such as drug delivery vehicles and nanoparticles, often rely on modifying naturally-occurring soft matter, such as polymers and lipid vesicles, so that they possess useful behavior. Mesoscopic simulations allow in silico experiments to be easily and cheaply performed on complex, soft materials requiring as input only the molecular structure of the constituents at a coarse-grained level. They can therefore act as a guide to experimenters prior to performing costly assays. Additionally, mesoscopic simulations provide the only currently feasible window on the length and time scales relevant to important biophysical processes such as vesicle fusion. We describe here recent work using Dissipative Particle Dynamics simulations to explore the structure and behavior of amphiphilic membranes, the fusion of vesicles, and the interactions between rigid nanoparticles and soft surfaces.

A Low-Cost Soft Coiled Sensor for Soft Robots

2016 ◽  
Author(s):  
Jianguo Zhao ◽  
Ali Abbas
Keyword(s):  
Optical Fibers ◽  
Closed Loop ◽  
Low Cost ◽  
Soft Materials ◽  
Soft Sensor ◽  
Soft Sensors ◽  
Soft Robots ◽  
Conductive Liquid ◽  
Loop Control ◽  
Sewing Threads

Soft robots made from soft materials can closely emulate biological system using simple soft mechanical structures. Compared with traditional rigid-link robots, they are safe to work with humans and can adapt to confined environments. As a result, they are widely used for various robotic locomotions and manipulations. Nevertheless, for soft robots, being able to sense its state to enable closed-loop control using soft sensors remains a challenge. Existing sensors include external sensors such as camera systems, electromagnetic tracking systems, and internal sensors such as optical fibers, conductive liquid, and carbon black filled strips. In this paper, we investigate a new soft sensor made from low-cost conductive nylon sewing threads. By continuously inserting twists into a thread under some weight, coils can be formed to enable a coiled soft sensor. The resistance of the sensor varies with the change of length. The fabrication and experiments for this new coiled sensor is described in this paper. Embedding this sensor to a 3D printed soft manipulator demonstrates the sensing capability. Compared to existing soft sensors, the coiled sensor is low-cost, easy to fabricate, and can also be used as an actuator. It can be embedded to any soft robot to measure the deformation for closed-loop feedback control.

scholarly journals Softer is Harder: What Differentiates Soft Robotics from Hard Robotics?

MRS Advances ◽  
2018 ◽  
Vol 3 (28) ◽  
pp. 1557-1568 ◽  
Author(s):  
Gursel ALICI
Keyword(s):  
Smart Materials ◽  
Control Algorithm ◽  
Soft Materials ◽  
Power Source ◽  
Stretchable Electronics ◽  
Power Requirement ◽  
Soft Robots ◽  
Hard Materials ◽  
Morphological Computation ◽  
Bulk Elastic Modulus

ABSTRACTThis paper reports on what differentiates the field of soft (i.e. soft-bodied) robotics from the conventional hard (i.e. rigid-bodied) robotics. The main difference centres on seamlessly combining the actuation, sensing, motion transmission and conversion mechanism elements, electronics and power source into a continuum body that ideally holds the properties of morphological computation and programmable compliance (i.e. softness). Another difference is about the materials they are made of. While the hard robots are made of rigid materials such as metals and hard plastics with a bulk elastic modulus of as low as 1 GPa, the monolithic soft robots should be fabricated from soft and hard materials or from a strategic combination of them with a maximum elasticity modulus of 1 GPa. Soft smart materials with programmable mechanical, electrical and rheological properties, and conformable to additive manufacturing based on 3D printing are essential to realise soft robots. Selecting the actuation concept and its power source, which is the first and most important step in establishing a robot, determines the size, weight, performance of the soft robot, the type of sensors and their location, control algorithm, power requirement and its associated flexible and stretchable electronics. This paper outlines how crucial the soft materials are in realising the actuation concept, which can be inspired from animal and plant movements.

Research progress of field-induced soft smart materials

2018 ◽  
Vol 32 (18) ◽  
pp. 1840010 ◽  
Author(s):  
Han Wu ◽  
Zhi Chao Xu ◽  
Jin Bo Wu ◽  
Wei Jia Wen
Keyword(s):  
Magnetic Field ◽  
Smart Materials ◽  
Soft Matter ◽  
Soft Materials ◽  
Magnetorheological Fluid ◽  
Electrorheological Fluid ◽  
Research Area ◽  
Research Progress ◽  
Polymer Gel ◽  
Field Temperature

The field-induced soft smart materials are a kind of soft matter whose macroscopic properties (mechanical, or optical) can be significantly and actively controlled and manipulated by external fields such as magnetic field, electric field, temperature or light. In this paper, we briefly review the research and application progress of the field-induced soft smart materials in recent years and discuss the development problems and trend in this research area. In particular, we focus on three typical field-induced soft materials of smart materials: magnetorheological fluid, electrorheological fluid, and temperature and light sensitive polymer gel.

scholarly journals A Pneumatic Generator Based on Gas-Liquid Reversible Transition for Soft Robots

Actuators ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 103
Author(s):  
Guolong Zhang ◽  
Guilin Yang ◽  
Yimin Deng ◽  
Tianjiang Zheng ◽  
Zaojun Fang ◽  
...  
Keyword(s):  
Smart Materials ◽  
Load Capacity ◽  
Angular Displacement ◽  
Quadratic Function ◽  
Air Cooling ◽  
Soft Robots ◽  
Reversible Transformation ◽  
Exponential Term ◽  
Reversible Transition ◽  
Gas Volume

The soft robots actuated by pressure, cables, thermal, electrosorption, combustion and smart materials are usually faced with the problems of poor portability, noise, weak load capacity, small deformation and high driving voltages. In this paper, a novel pneumatic generator for soft robots based on the gas-liquid reversible transition is proposed, which has the advantages of large output force, easy deformation, strong load capacity and high flexibility. The pressure of the pneumatic generator surges or drops flexibly through the reversible transformation between liquid and gas phase, making the soft actuator stretch or contract regularly, without external motors, compressors and pressure-regulating components. The gas-liquid reversible-transition actuation process is modeled to analyze its working mechanism and characteristics. The pressure during the pressurization stage increases linearly with a rate regulated by the heating power and gas volume. It decreases exponentially with the exponential term as a quadratic function of time at the fast depressurization stage, while with the exponential term as a linear function of time at the slow depressurization stage. The drop rate can be adjusted by changing the gas volume and cooling conditions. Furthermore, effectiveness has been verified through experiments of the prototype. The pressure reaches 25 bar with a rising rate of +3.935 bar/s when 5 mL weak electrolyte solution is heated at 800 W, and the maximum depressurization rate in air cooling is –3.796 bar/s. The soft finger actuated by the pneumatic generator can bend with an angular displacement of 67.5°. The proposed pneumatic generator shows great potential to be used for the structure, driving and sensing integration of artificial muscles.

scholarly journals Sensitivity Analysis for Microscopic Crowd Simulation

Algorithms ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 162
Author(s):  
Marion Gödel ◽  
Rainer Fischer ◽  
Gerta Köster
Keyword(s):  
Sensitivity Analysis ◽  
Low Cost ◽  
Input Parameter ◽  
Dimensional Subspace ◽  
Crowd Simulation ◽  
Pedestrian Dynamics ◽  
Sensitivity Indices ◽  
Expensive Problems ◽  
Influential Parameters ◽  
Typical Scenario

Microscopic crowd simulation can help to enhance the safety of pedestrians in situations that range from museum visits to music festivals. To obtain a useful prediction, the input parameters must be chosen carefully. In many cases, a lack of knowledge or limited measurement accuracy add uncertainty to the input. In addition, for meaningful parameter studies, we first need to identify the most influential parameters of our parametric computer models. The field of uncertainty quantification offers standardized and fully automatized methods that we believe to be beneficial for pedestrian dynamics. In addition, many methods come at a comparatively low cost, even for computationally expensive problems. This allows for their application to larger scenarios. We aim to identify and adapt fitting methods to microscopic crowd simulation in order to explore their potential in pedestrian dynamics. In this work, we first perform a variance-based sensitivity analysis using Sobol’ indices and then crosscheck the results by a derivative-based measure, the activity scores. We apply both methods to a typical scenario in crowd simulation, a bottleneck. Because constrictions can lead to high crowd densities and delays in evacuations, several experiments and simulation studies have been conducted for this setting. We show qualitative agreement between the results of both methods. Additionally, we identify a one-dimensional subspace in the input parameter space and discuss its impact on the simulation. Moreover, we analyze and interpret the sensitivity indices with respect to the bottleneck scenario.

Design and Implementation of an Ionic-Polymer-Metal-Composite Aquatic Biomimetic Robot

2011 ◽  
Author(s):  
Yi-chu Chang ◽  
Won-jong Kim
Keyword(s):  
Input Signal ◽  
Smart Materials ◽  
Metal Composite ◽  
Ionic Polymer Metal Composite ◽  
Walking Robot ◽  
Ionic Polymer ◽  
Square Wave ◽  
Polymer Metal ◽  
Biomimetic Robot ◽  
Two Degree Of Freedom

Smart materials have been used in various applications. In this paper, a walking robot with six two-degree-of-freedom (2-DOF) legs made of ionic polymer metal composite (IPMC) is designed and implemented. Each leg can work as both a supporter and a driver, closely mimicking a real insect. To support and drive the robot, thicker (around 1 mm in thickness) IPMC strips were fabricated and used, and a 0.2-rad/s square wave is given as an input signal. The IPMC strips exhibit better performance in response to the square wave (8 mm) than sawtooth (4 mm) and sinusoidal (6 mm) waves in deflection. By applying this input signal in sequence, all the IPMC strips bend and walk in the form of six legs. In addition, thin magnet wires were used to supply power to each strip to prevent from confining the motion of our robot. Six lower legs are divided into two groups that work in the opposite directions to move the robot forward by turns. Upper legs are also divided into two groups to lift up their lower legs from making the robot to move back to the same place. The sizes of the IPMC strips and our robot (102 mm × 80 mm × 43 mm) were decided to exhibit better performance (0.5 mm/s) according to our tests.

Towards Parallel Cable-Driven Pantographs

2011 ◽  
Author(s):  
Simon Perreault ◽  
Philippe Cardou ◽  
Cle´ment Gosselin
Keyword(s):  
Low Cost ◽  
Output Link ◽  
Static Balancing ◽  
New Class ◽  
Nonlinear Springs ◽  
Preliminary Validation ◽  
Important Challenge ◽  
History Of ◽  
Working Principle ◽  
Two Degree Of Freedom

We propose a new class of pantographs, i.e., of mechanisms that allow the reproduction of the displacements of an input link, the master, with an output link, the slave. The application we envision for these devices is the telemanipulation of objects from small distances, at low cost, where magnetic fields or other design constraints prohibit the use of electromechanical systems. Despite the long history of pantographs, which were invented in the 17th century, the class of pantographs proposed here is new, as it relies on parallel cable-driven mechanisms to transmit the motion. This allows the reproduction of rigid-body displacements, while previous pantographs were limited to point displacements. This important characteristic and others are described in the paper. One important challenge in the design of the proposed systems is that the cables must remain taut at all time. We address this issue by introducing nonlinear springs that passively maintain a minimum tension in the cables, while approximating static balancing of the mechanism over its workspace. Approximating static balancing allows the forces applied at the slave to reflect more accurately at the master, and vice versa. As a preliminary validation, a two-degree-of-freedom parallel cable-driven pantograph is designed. A prototype of this apparatus that does not include approximate static balancing is built, which demonstrates the working principle of these mechanisms.

Design and Construction of a Low Cost of Solar Tracker Two Degree of Freedom (DOF) Based On Arduino

2020 ◽  
Author(s):  
Marthen Dangu Elu Beily ◽  
Rusman Sinaga ◽  
Zilman Syarif ◽  
Mychael G Pae ◽  
Rochani Rochani
Keyword(s):  
Low Cost ◽  
Degree Of Freedom ◽  
Solar Tracker ◽  
Two Degree Of Freedom ◽  
Design And Construction

1. The science of softness

2020 ◽  
pp. 1-18
Author(s):  
Tom McLeish
Keyword(s):  
Scientific Community ◽  
Soft Matter ◽  
Soft Materials ◽  
Visionary Leadership ◽  
Slow Dynamics ◽  
Length Scales ◽  
New Science ◽  
Motion Structure

‘The science of softness’ provides a brief history and overview of soft matter science. The development of soft matter science was propelled by a combination of communication within the scientific community; intrinsic conceptual overlap and commonality; and visionary leadership from a small number of pioneering scientists. Chemistry proved as essential an ingredient to the new science of soft matter as ideas and techniques from physics. The characteristics of soft matter include motion; structure on intermediate length scales; slow dynamics; and universality. Microscopy is the most obvious and direct example of experimental tools applied across the gamut of soft materials.

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