Twelve Degree of Freedom Baby Humanoid Head Using Shape Memory Alloy Actuators

2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Yonas Tadesse ◽  
Dennis Hong ◽  
Shashank Priya
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Kinematic Model ◽  
Complementary Metal Oxide Semiconductor ◽  
The Body ◽  
Oxide Semiconductor ◽  
Simulink Model ◽  
The Face ◽  
Nonlinear Dynamics Model ◽  
Driving Circuit

A biped mountable robotic baby head was developed using a combination of Biometal fiber and Flexinol shape memory alloy actuators (SMAs). SMAs were embedded in the skull and connected to the elastomeric skin at control points. An engineered architecture of the skull was fabricated, which incorporates all the SMA wires with 35 routine pulleys, two firewire complementary metal-oxide semiconductor cameras that serve as eyes, and a battery powered microcontroller base driving circuit with a total dimension of 140×90×110 mm3. The driving circuit was designed such that it can be easily integrated with a biped and allows programming in real-time. This 12DOF head was mounted on the body of a 21DOF miniature bipedal robot, resulting in a humanoid robot with a total of 33DOFs. Characterization results on the face and associated design issues are described, which provides a pathway for developing a humanlike facial anatomy using wire-based muscles. Numerical simulation based on SIMULINK was conducted to assess the performance of the prototypic robotic face, mainly focusing on the jaw movement. The nonlinear dynamics model along with governing equations for SMA actuators containing transcendental and switching functions was solved numerically and a generalized SIMULINK model was developed. Issues related to the integration of the robotic head with a biped are discussed using the kinematic model.

scholarly journals Development of Subcarangiform Bionic Robotic Fish Propelled by Shape Memory Alloy Actuators

2021 ◽  
Vol 71 (1) ◽  
pp. 94-101
Author(s):  
M. Muralidharan ◽  
I.A. Palani
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Kinematic Model ◽  
Open Loop ◽  
Robotic Fish ◽  
Water Medium ◽  
Light Weight ◽  
Caudal Fin ◽  
Locomotion Pattern ◽  
Sma Spring

In this paper, a shape memory alloy (SMA) actuated subcarangiform robotic fish has been demonstrated using a spring based propulsion mechanism. The bionic robotic fish developed using SMA spring actuators and light weight 3D printed components can be employed for under water applications. The proposed SMA spring-based design without conventional motor and other rotary actuators was able to achieve two-way shape memory effect and has reproduced the subcarangiform locomotion pattern. The positional kinematic model has been developed and the dynamics of the proposed mechanism were analysed and simulated using Automated Dynamic Analysis of Mechanical Systems (ADAMS). An open loop Arduino-relay based switching control has been adopted to control the periodic actuation of the SMA spring mechanism. The undulation of caudal fin in air and water medium has been analysed. The caudal fin and posterior body of the developed fish prototype have taken part in undulation resembling subcarangiform locomotion pattern and steady swimming was achieved in water with a forward velocity of 24.5 mm/s. The proposed design is scalable, light weight and cost effective which may be suitable for underwater surveillance application.

A shape memory alloy–actuated soft crawling robot based on adaptive differential friction and enhanced antagonistic configuration

2020 ◽  
Vol 31 (16) ◽  
pp. 1920-1934 ◽  
Author(s):  
Chen Liang ◽  
Yongquan Wang ◽  
Tao Yao ◽  
Botao Zhu
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Stride Length ◽  
Parametric Design ◽  
Thermoplastic Polyurethane ◽  
Interaction Mechanism ◽  
Experimental Tests ◽  
The Body ◽  
3D Printed ◽  
Miniature Robot

This article presents a soft crawling robot prototype with a simple architecture inspired by inchworms. The robot functionally integrates the torso (body) and feet in a monolithic curved structure that only needs a single shape memory alloy coil and differential friction to actuate it. A novel foot configuration is proposed, which makes the two feet, with an anti-symmetrical friction layout, can be alternately anchored, to match the contraction–recovery sequence of the body adaptively. Based on the antagonistic configuration between the shape memory alloy actuator and the elastic body, a vertically auxiliary spring was adopted to enhance the interaction mechanism. Force and kinematic analysis was undertaken, focusing on the parametric design of the special foot configuration. A miniature robot prototype was then 3D-printed (54 mm in length and 9.77 g in weight), using tailored thermoplastic polyurethane elastomer as the body material. A series of experimental tests and evaluations were carried out to assess its performance under different conditions. The results demonstrated that under appropriate actuation conditions, the compact robot prototype could accomplish a relative speed of 0.024 BL/s (with a stride length equivalent to 27% of its body length) and bear a load over five times to its own weight.

A novel smart assistive knee brace incorporated with shape memory alloy wire actuator

2020 ◽  
Vol 31 (13) ◽  
pp. 1543-1556
Author(s):  
Navid Moslemi ◽  
Soheil Gohari ◽  
Farzin Mozafari ◽  
Mohsen Gol Zardian ◽  
Colin Burvill ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Controller Design ◽  
Compliant Mechanism ◽  
The Body ◽  
Entire Body ◽  
Knee Brace ◽  
Design Concepts ◽  
Feed Forward Controller ◽  
Actuator Design

The knee plays a significant role in locomotion and stability of the entire body through supporting the body weight and assisting the lower body kinematics during walking. However, the knee is at constant risk of becoming weakened due to disease, age, and accidents. One approach to treating weakened knee is wearing an assistive knee brace. To design a clinical knee brace, many factors such as weight and compliant mechanism should be considered. In this study, a novel smart assistive knee brace mechanism incorporated with wire actuators made of shape memory alloys is proposed to ameliorate the issues associated with weight and flexibility of existing brace designs. Unlike earlier studies, the proposed orthosis includes pressure sensor, shape memory actuator, and smart linkage. Furthermore, two distinct shape memory alloy actuator design concepts with improved stiffness are developed, and the best option is chosen systematically and prototyped. The novel mechanism proposed in this research overcomes the weight of the lower limb during swing phase using the combined shape memory alloy actuation and feed-forward controller design. As such, it can be used as a potential replacement to its conventional counterparts when the higher weight reduction as well as a flexible and controllable mechanism are simultaneously sought.

Helical Kirigami-Enabled Centimeter-Scale Worm Robot With Shape-Memory-Alloy Linear Actuators

2015 ◽  
Vol 7 (2) ◽  
Author(s):  
Ketao Zhang ◽  
Chen Qiu ◽  
Jian S. Dai
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Kinematic Model ◽  
Parallel Structure ◽  
Geometrical Parameters ◽  
Parallel Structures ◽  
Complete Procedure ◽  
Motion Characteristics

The wormlike robots are capable of imitating amazing locomotion of slim creatures. This paper presents a novel centimeter-scale worm robot inspired by a kirigami parallel structure with helical motion. The motion characteristics of the kirigami structure are unravelled by analyzing the equivalent kinematic model in terms of screw theory. This reveals that the kirigami parallel structure with three degrees-of-freedom (DOF) motion is capable of implementing both peristalsis and inchworm-type motion. In light of the revealed motion characteristics, a segmented worm robot which is able to imitate contracting motion, bending motion of omega shape and twisting motion in nature is proposed by integrating kirigami parallel structures successively. Following the kinematic and static characteristics of the kirigami structure, actuation models are explored by employing the linear shape-memory-alloy (SMA) coil springs and the complete procedure for determining the geometrical parameters of the SMA coil springs. Actuation phases for the actuation model with two SMA springs are enumerated and with four SMA springs are calculated based on the Burnside's lemma. In this paper, a prototype of the worm robot with three segments is presented together with a paper-made body structure and integrated SMA coil springs. This centimeter-scale prototype of the worm robot is lightweight and can be used in confined environments for detection and inspection. The study presents an interesting approach of integrating SMA actuators in kirigami-enabled parallel structures for the development of compliant and miniaturized robots.

Low-Power, Minimal-Heat Exposure Shape Memory Alloy (SMA) Actuators for On-Body Soft Robotics

2019 ◽  
Author(s):  
Simon Ozbek ◽  
Esther Foo ◽  
J. Walter Lee ◽  
Nicholas Schleif ◽  
Brad Holschuh
Keyword(s):  
Low Temperature ◽  
Shape Memory Alloy ◽  
Low Power ◽  
Shape Memory ◽  
Room Temperature ◽  
Dynamic Compression ◽  
Heat Exposure ◽  
The Body ◽  
Compression Garments ◽  
Sma Actuators

In the world of soft-robotic medical devices, there is a growing need for low profile, non-rigid, and lower power actuators for soft exoskeletons and dynamic compression garments. Advanced compression garments with integrated shape memory materials have been developed recently to alleviate the functional and usability limitations associated with traditional compression garments. These advanced garments use contractile shape memory alloy (SMA) coil actuators to produce dynamic compression on the body through selective heating of the SMA material. While these garments can create spatially- and temporally-controllable compression, typical SMA materials (e.g., 70°C Flexinol) consume considerable power and require considerable thermal insulation to protect the wearer during the heating phase of the SMA actuation. Alternative SMA materials (e.g., NiTi #8 by Fort Wayne Metals, Inc.) transform below room temperature and do so using no applied electrical power and generate no waste heat. However, these materials are challenging to dynamically control and require active refrigeration to reset to material. In theory, low-temperature SMA actuators made from materials like NiTi #8 may maintain additional dynamic actuation capacity once equilibrated to room temperature (i.e., the material may not fully transform), as the SMA phase transformation temperature window expands when the material experiences applied stress. This paper investigates this possibility: we manufactured and tested low-temperature NiTi coil actuators to determine the magnitude of the additional force that can be generated via Joule heating once the material has equilibrated to room temperature. SMA spring actuators made from NiTi #8 consumed 84% less power and stabilized at significantly lower temperatures (26.0°C vs. 41.2°C) than SMA springs made from 70°C Flexinol, when actuated at identically fixed displacements (100% nominal strain) and when driven to produce equal forces (∼3.35N). This demonstration of low-power, minimal-heat exposure SMA actuation holds promise for many future wearable actuation applications, including dynamic compression garments.

Helical Kirigami-Inspired Centimeter-Scale Worm Robot With Shape-Memory-Alloy Actuators

2014 ◽  
Author(s):  
Ketao Zhang ◽  
Chen Qiu ◽  
Jian S. Dai
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
The Body ◽  
Helical Motion ◽  
Body Structure ◽  
New Approach ◽  
Sma Actuators ◽  
Parallel Kinematic ◽  
Motion Characteristics

The worm-like robots are capable of imitating the amazing locomotion of the long and thin creature. This paper presents a novel centimeter-scale worm robot inspired by a kirigami-fold which is a variation of origami with helical motion. The body structure is extracted from the kirigami structure and its motion characteristics are analyzed in terms of kinematic principles. This leads to identification of the capability of the segmented worm robot with integrated parallel kirigami structures to imitate contracting motion, omega-shaped bending motion and twisting motion of the locomotion in nature. A prototype of the worm robot with three segments is fabricated with paper-made body structure and actuated by shape-memory-alloy (SMA) coil springs. The robot is lightweight and can be used in confined environments for detection and inspection. The study creates a new approach of integrating SMA actuators in origami-enabled parallel kinematic structures for the development of compliant and miniaturized robots including the presented worm robot.

scholarly journals CMOS Interfaces for Internet-of-Wearables Electrochemical Sensors: Trends and Challenges

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 150 ◽  
Author(s):  
Michele Dei ◽  
Joan Aymerich ◽  
Massimo Piotto ◽  
Paolo Bruschi ◽  
Francisco del Campo ◽  
...  
Keyword(s):  
Electrochemical Sensors ◽  
Biological Fluids ◽  
Complementary Metal Oxide Semiconductor ◽  
The Body ◽  
Oxide Semiconductor ◽  
Non Invasive ◽  
Wide Range ◽  
Specific Stimulation ◽  
Iot Devices ◽  
Natural Way

Smart wearables, among immediate future IoT devices, are creating a huge and fast growing market that will encompass all of the next decade by merging the user with the Cloud in a easy and natural way. Biological fluids, such as sweat, tears, saliva and urine offer the possibility to access molecular-level dynamics of the body in a non-invasive way and in real time, disclosing a wide range of applications: from sports tracking to military enhancement, from healthcare to safety at work, from body hacking to augmented social interactions. The term Internet of Wearables (IoW) is coined here to describe IoT devices composed by flexible smart transducers conformed around the human body and able to communicate wirelessly. In addition the biochemical transducer, an IoW-ready sensor must include a paired electronic interface, which should implement specific stimulation/acquisition cycles while being extremely compact and drain power in the microwatts range. Development of an effective readout interface is a key element for the success of an IoW device and application. This review focuses on the latest efforts in the field of Complementary Metal–Oxide–Semiconductor (CMOS) interfaces for electrochemical sensors, and analyses them under the light of the challenges of the IoW: cost, portability, integrability and connectivity.

An Assessment of the Body Joint Bending Actuator using a Shape Memory Alloy

2010 ◽  
Vol 10 (17) ◽  
pp. 1973-1977 ◽  
Author(s):  
Yao-Jen Lai ◽  
Long-Jyi Yeh ◽  
Min-Chie Chiu
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
The Body ◽  
Bending Actuator ◽  
Body Joint

scholarly journals A CMOS RF Receiver with Improved Resilience to OFDM-Induced Second-Order Intermodulation Distortion for MedRadio Biomedical Devices and Sensors

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5303
Author(s):  
Yongho Lee ◽  
Shinil Chang ◽  
Jungah Kim ◽  
Hyunchol Shin
Keyword(s):  
Integrated Circuit ◽  
Communication Systems ◽  
Complementary Metal Oxide Semiconductor ◽  
Low Noise ◽  
Second Order ◽  
The Body ◽  
Oxide Semiconductor ◽  
Biomedical Devices ◽  
Passive Mixer ◽  
Rf Receiver

A MedRadio RF receiver integrated circuit for implanted and wearable biomedical devices must be resilient to the out-of-band (OOB) orthogonal frequency division modulation (OFDM) blocker. As the OFDM is widely adopted for various broadcasting and communication systems in the ultra-high frequency (UHF) band, the selectivity performance of the MedRadio RF receiver can severely deteriorate by the second-order intermodulation (IM2) distortion induced by the OOB OFDM blocker. An analytical investigation shows how the OFDM-induced IM2 distortion power can be translated to an equivalent two-tone-induced IM2 distortion power. It makes the OFDM-induced IM2 analysis and characterization process for a MedRadio RF receiver much simpler and more straightforward. A MedRadio RF receiver integrated circuit with a significantly improved resilience to the OOB IM2 distortion is designed in 65 nm complementary metal-oxide-semiconductor (CMOS). The designed RF receiver is based on low-IF architecture, comprising a low-noise amplifier, single-to-differential transconductance stage, quadrature passive mixer, trans-impedance amplifier (TIA), image-rejecting complex bandpass filter, and fractional phase-locked loop synthesizer. We describe design techniques for the IM2 calibration through the gate bias tuning at the mixer, and the dc offset calibration that overcomes the conflict with the preceding IM2 calibration through the body bias tuning at the TIA. Measured results show that the OOB carrier-to-interference ratio (CIR) performance is significantly improved by 4–11 dB through the proposed IM2 calibration. The measured maximum tolerable CIR is found to be between −40.2 and −71.2 dBc for the two-tone blocker condition and between −70 and −77 dBc for the single-tone blocker condition. The analytical and experimental results of this work will be essential to improve the selectivity performance of a MedRadio RF receiver against the OOB OFDM-blocker-induced IM2 distortion and, thus, improve the robustness of the biomedical devices in harsh wireless environments in the MedRadio and UHF bands.

Finger-Like Mechanism Using Bending Shape Memory Alloys

2020 ◽  
Author(s):  
Hussein F. M. Ali ◽  
Hangyeol Baek ◽  
Taesoo Jang ◽  
Youngshik Kim
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Kinematic Model ◽  
Coordinated Control ◽  
Force Sensor ◽  
Biologically Inspired ◽  
Sma Actuators ◽  
Finger Flexion ◽  
Compliant Actuation ◽  
Sma Actuator

Abstract A biologically inspired finger-like mechanism similar to human musculoskeletal system is developed based on Shape Memory Alloy (SMA). SMA actuators are inspiring the design of a modular finger part with compact and compliant actuation. This paper describes a three-segmented finger-like mechanism. This mechanism is composed of six bending Shape Memory Alloy (SMA) actuators. As a result, our finger mechanism is compact and compliant. The insider three SMA actuator are used for finger flexion while the outsider three SMA actuators are for extension. Each segment of this mechanism can be bent and/or extended independently by actuating a corresponding bending SMA actuator. Furthermore, full bending motion can be achieved by applying coordinated control of the three SMA actuators. Bending and stretching motions of the proposed mechanism are finally demonstrated. The work space of the three-segment finger is studied to verify the reachable points by the end tip. The kinematic model is developed to study the motion of the mechanism. The performance evaluation is executed using force sensor and a temperature monitoring of the corresponding SMA actuators. The simulation and experimental results indicate that the SMA-based finger module can achieve effectively the desired motions as designed.

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