Smart Soft Composite: An Integrated 3D Soft Morphing Structure Using Bend-Twist Coupling of Anisotropic Materials

Ahn, Sung-Hoon,Lee, Kyung-Tae,Kim, Hyung-Jung,Wu, Renzhe,Kim, Ji-Soo,Song, Sung-Hyuk 한국정밀공학회 2012 International Journal of Precision Engineering and Vol.13 No.4

Traditionally, hard or high-stiffness materials are used to achieve morphing but only with limited magnitudes of deformation. Soft and low-stiffness materials are required to implement soft morphing with large deformations. In this paper, a novel concept for soft morphing structures that makes use of smart soft composites (SSC) is introduced. These materials have the following characteristics: 1) Large deformations from smart actuators and soft anisotropic materials embedded in a soft matrix material, 2) Utilization of the coupling effect for in-plane/bending/twisting deformations of the morphing structure to achieve complex morphed shapes, 3) Semi-automated three-dimensional (3D) fabrication via 3D printing processes. Classical lamination theory is used to express in-plane deformation, out-of-plane deformation, and twisting and coupling of these deformations. 3D-printed-scaffold and/or weaving methods can be used to fabricate anisotropic materials for SSCs. An integrated SSC in a cantilever shape is fabricated using SMA (Shape memory alloy)/ABS/PDMS and tested as an example to show large deformation with bend/twist coupling effect.

Paper : Smart Phone Robot Made of Smart Soft Composite (SSC)

( Wei Wang ),( Hugo Rodrigue ),( Jang-yeob Lee ),( Min-woo Han ),( Sung-hoon Ahn ) 한국복합재료학회 2015 Composites research Vol.28 No.2

Soft morphing robotics making use of smart material and based on biomimetic principles are capable of continuous locomotion in harmony with its environment. Since these robots do not use traditional mechanical components, they can be built to be light weight and capable of a diverse range of locomotion. This paper illustrates a flexible smart phone robot made of smart soft composite (SSC) with inchworm-like locomotion capable of two-way linear motion. Since rigid components are embedded within the robot, bending actuators with embedded rigid segments were investigated in order to obtain the maximum bending curvature. To verify the results, a simple mechanical model of this actuator was built and compared with experimental data. After that, the flexible robot was implemented as part of a smart phone robot where the rigid components of the phone were embedded within the matrix. Then, experiments were conducted to test the smart phone robot actuation force under different deflections to verify its load carrying capability. After that, the communication between the smart phone and robot controller was implemented and a corresponding phone application was developed. The locomotion of the smart phone robot actuated through an independent controller was also tested.

Cross-Shaped Twisting Structure Using SMA-Based Smart Soft Composite

안성훈,Hugo Rodrigue,WANGWEI,Binayak Bhandari,한민우 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.1 No.2

Smart soft compositeThis paper introduces a novel geometry for a pure-twisting soft morphing actuator that improves the stability of the actuator and allows it to obtain a larger twisting angle. The smart soft composite (SSC) actuator uses pair of NiTi shape memory alloy (SMA) wires embedded in a cross-shaped polydimethylsiloxane (PDMS) matrix at constant and opposite eccentricity across the cross-section in opposite directions in order to produce a twisting motion. To evaluate the twisting performance of the cross-shaped actuator, specimens with rectangular cross-sections and cross-shaped cross-sections are made and their twist angles are measured and compared. Results show that the cross-shaped actuator is capable of a higher twisting rate by using a thinner flange due to a more stable twisting motion. (SSC), Twisting actuator, Shape memory alloy (SMA), Cross This paper introduces a novel geometry for a pure-twisting soft morphing actuator that improves the stability of the actuator and allows it to obtain a larger twisting angle. The smart soft composite (SSC) actuator uses pair of NiTi shape memory alloy (SMA) wires embedded in a cross-shaped polydimethylsiloxane (PDMS) matrix at constant and opposite eccentricity across the cross-section in opposite directions in order to produce a twisting motion. To evaluate the twisting performance of the cross-shaped actuator, specimens with rectangular cross-sections and cross-shaped cross-sections are made and their twist angles are measured and compared. Results show that the cross-shaped actuator is capable of a higher twisting rate by using a thinner flange due to a more stable twisting motion.

지능형 연성 복합재를 활용한 유연 생체모사 수중 로봇

송성혁,김민수,김민철,안성훈 제어로봇시스템학회 2015 제어로봇시스템학회 국내학술대회 논문집 Vol.2015 No.5

Modeling of Smart Soft Composite Twisting Actuators

H. Rodrigue(로드리그 휴고),W.Wang(왕웨이),M. C. Kim(김민철),S. H. Ahn(안성훈) 한국정밀공학회 2015 한국정밀공학회 학술발표대회 논문집 Vol.2015 No.12월

A shape memory alloy–based soft morphing actuator capable of pure twisting motion

Rodrigue, Hugo,Bhandari, Binayak,Han, Min-Woo,Ahn, Sung-Hoon SAGE Publications 2015 Journal of intelligent material systems and struct Vol.26 No.9

<P>This article introduces a novel design for a soft morphing actuator capable of pure twisting motion through a pair of shape memory alloy wires embedded in a polydimethylsiloxane matrix at constant and opposite eccentricity across the cross section in opposite directions. This report introduces the design of the actuator, the manufacturing method, and experimental results for the twisting angle and twisting force when varying the dimensions of the matrix of the actuator. Afterward, a simple model is applied to verify the effect of matrix dimensions on the twisting angle of the actuator. The results show that there is an optimal actuator thickness for both the twisting angle and the twisting force of the actuator, that there is a trade-off between the twisting angle and the twisting force for the actuator's thickness, and that a longer length is better for both metrics within the tested dimensions.</P>

지능형 연성 복합재 구조체를 활용한 고속 구동기

송성혁(S. H. Song),이장엽(J. Y. Lee),로드리그 유고(H. Rodrigue),안성훈(S. H. Ahn) 한국정밀공학회 2015 한국정밀공학회 학술발표대회 논문집 Vol.2015 No.12월

Deformable-wheel robot based on soft material

이대영,고제성,김지석,김승원,조규진 한국정밀공학회 2013 International Journal of Precision Engineering and Vol.14 No.8

Soft robotics, a concept contrary to conventional “hard” robotics, is a robot design methodology that uses soft materials inspired by nature. In contrast to a hard robot, a soft robot is composed of soft and flexible materials that blur the distinction between an actuator and a structure, which leads to unique characteristics that cannot be found in a conventional hard robot. This paper presents our approach to the issues that arise when the concept of soft robotics is applied to a wheeled robot. The compliance of the wheel diversifies its potential movement and allows for a high degree of adaptability to the environment. Although the wheel radius of the robot is 50 mm, it can pass through a 30 mm gap and climb a 45 mm step. While soft robotics displays properties whose performance can be challenging to implement, it also enables us to create complex forms of movement in a cheaper and simpler way. We expect that this kind of approach can provide a new design method for a deformable wheel.

Soft morphing hand driven by SMA tendon wire

Kim, H.I.,Han, M.W.,Song, S.H.,Ahn, S.H. Elsevier Science Ltd 2016 Composites Part B, Engineering Vol.105 No.-

Most existing approaches to developing robotic manipulators or artificial hands have used rigid components, with joints, linkages, gears, and motors. Rigid robotic systems can perform tasks with precise and articulated motion, but require complex integrated feedback-based control systems. Soft robotics is an emerging research field that uses deformable materials to build systems that are compliant and adaptable via simple integrated mechanisms, enabling biomimetic behavior with compact systems. Here, we report a novel tendon-driven bending actuator using smart soft composite (SSC) and shape memory alloy (SMA). First, an artificial finger was designed based on a SMA wire and a sliding mechanism, which mimics flexion of the human hand. This artificial finger has a soft hinge structure to enable the bending motion of the actuator. Experiments were conducted to evaluate the bending and load resistance of the artificial finger, and an optimal material composition was identified. The bending performance of the actuator was measured with various numbers of glass fiber sheets, and two-layered actuator showed the best performance in terms of the trade-off relationship between the bending capacity and the load holding capacity - bending angle of 305<SUP>o</SUP> with weight of 20 g and bending angle of 61<SUP>o</SUP> with weight of 60 g. Finally, a prototype robotic hand was then developed using four tendon-driven SSC fingers and a thumb, and grasping capabilities were demonstrated with various objects with diverse shapes.

Curved shape memory alloy-based soft actuators and application to soft gripper

Rodrigue, H.,Wang, W.,Kim, D.R.,Ahn, S.H. ELSEVIER (APPLIED SCIENCE) 2017 COMPOSITE STRUCTURES -BARKING THEN OXFORD- Vol.176 No.-

The performance of shape-memory alloy (SMA)-based soft actuators depends largely on the configuration of the cross-section of the actuator. A shape memory alloy-based curved bending actuator manufactured by double casting is introduced in this work. Curved actuators are capable of larger maximum bending angles with the same cross-section configuration as a straight actuator, and both the design method and the casting method proposed in this work are novel for this type of actuator. The effect of the initial bending angle due to the curvature of the actuator and of non-uniform initial curvatures on the maximum bending angle was tested. A model based on the thermoconstitutive model of SMA with a geometrical analysis of the deformation of the actuator was used to estimate the effect of the initial curvature on the maximum bending angle of the actuator. Finally, multiple curved actuators were implemented as a simple gripper and the lifting force of straight and curved actuators were compared, and the curved gripper has a lifting force nearly three times larger than the straight gripper. This type of concept can be used to tailor the force, deformed shape and maximum deformation of SMA actuators.