scholarly journals SMA micro-hand implemented in small robot for generating gestures

2021 ◽  
Author(s):  
Ishikawa Takumi ◽  
Nagasawa Sumito
Keyword(s):  
Shape Memory Alloy ◽  
Response Times ◽  
Austenite Phase ◽  
Cooling Power ◽  
Robot Hand ◽  
Hand Size ◽  
Ni Alloy ◽  
Lower Temperature ◽  
Human Finger ◽  
Small Robot

AbstractResearch on robots that can be used for communication with humans has become popular in recent years. Communication robots should ideally be as small as an infant in order to reduce the user’s feeling of threat. In addition, non-verbal communication (such as gestures) is also important in facilitating smooth interactions between humans and robots. There are currently a few communication robots that are small sized and can generate hand gestures. In this paper, we propose a small robot hand, which is optimized for gesture communication by using a shape memory alloy (SMA). The SMA employed is a Ti–Ni alloy, which is used as an actuator. The SMA shrinks when it transforms into the austenite phase at temperatures higher than the transformation temperature. When it is in the martensitic phase at a lower temperature, it is expanded by an external force. Each finger of the robot hand is driven by an individual SMA wire. The specifications of the small robot including the hand size, operation angles in each finger joint, response times and power consumption were determined according to the human finger and existing small communication robots. These required specifications have been fulfilled by carefully designing the geometry and heating/cooling power control. A questionnaire-based survey was also conducted with a robot hand. The five-finger hand was successfully shown to generate recognizable symbolic gestures.

Self-Accommodation Mechanisms for Orthorhombic Martensite Formation in Sputtered Thin Films of Thermoelastic Ti(Nicu)

1993 ◽  
Vol 311 ◽  
Author(s):  
L. Chang ◽  
D. S. Grummon
Keyword(s):  
Thin Films ◽  
Orthorhombic Phase ◽  
Austenite Phase ◽  
Simultaneous Occurrence ◽  
Transmission Microscopy ◽  
Fine Grained ◽  
Orthorhombic Martensite ◽  
Austenite Grain ◽  
Lower Temperature ◽  
Accommodation Mechanism

ABSTRACTDirect observation of the self-accommodation morphology for orthorhombic martensite in Ti51.0Ni44.4Cu4.6 thin films has been accomplished by transmission microscopy of fine grained (<2μm) material prepared by triode magnetron sputtering. The films were observed to undergo, on cooling, two separate thermoelastic transformations in which the B2 austenite phase first transformed to an orthorhombic martensite with a =.291 nm, b =.425 nm and c =.450 nm followed by transformation to the monoclinic phase at lower temperature. The R-phase transformation was suppressed. Single grains contained as many as eight crystallographic variants of the orthorhombic phase, the majority of which were shaped as parallelograms bounded by {111}Ortho twin planes. The local self-accommodation mechanism produced combinations in which three adjacent variants shared a common {111}B2 pole. Although the majority of B19 variant domains accommodated themselves through {111}Ortho type twinning, a second accommodation mechanism, involving two sets of band-like martensite variants, bounded by {011}ortho twin planes, was also observed. Simultaneous occurrence of the {111}ortho and {011}ortho twinning modes, wihtin a single austenite grain, was not observed.

Magnetic Properties and Magnetocaloric Effect of Gd3Ni in Crystalline and Amorphous States

2012 ◽  
Vol 190 ◽  
pp. 355-358 ◽  
Author(s):  
D.A. Shishkin ◽  
N.V. Baranov ◽  
A.V. Proshkin ◽  
S.V. Andreev ◽  
A.S. Volegov
Keyword(s):  
Magnetic Field ◽  
Magnetocaloric Effect ◽  
Entropy Change ◽  
Rapid Quenching ◽  
Antiferromagnetic Order ◽  
Cooling Power ◽  
Ferromagnetic Behavior ◽  
Field Change ◽  
Ni Alloy ◽  
Magnetic Field Change

The liquid quenched Gd3Ni alloy is observed to exhibit a ferromagnetic behavior below TC = 117 K unlike crystalline compound having an antiferromagnetic order at T < TN = 99 K. Rapid quenching from the melt results in a considerable enhancement of the magnetocaloric effect in Gd3Ni at low magnetic fields. The maximal value of the isothermal magnetic entropy change at a magnetic field change of 20 kOe for the amorphous Gd3Ni surpasses by more than 8 times the SM value for the polycrystalline counterpart. The relative cooling power for the amorphous Gd3Ni alloy is estimated as 265 J kg-1 and 676 J kg-1 at a magnetic field change of 20 kOe and 50 kOe, respectively.

Temperature dependent deformation of the B2 austenite phase of a NiTi shape memory alloy

2013 ◽  
Vol 51 ◽  
pp. 103-121 ◽  
Author(s):  
O. Benafan ◽  
R.D. Noebe ◽  
S.A. Padula ◽  
A. Garg ◽  
B. Clausen ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Austenite Phase ◽  
Niti Shape Memory Alloy ◽  
Temperature Dependent

Temperature Memory Effect of Ti-Ni-Hf-Y High Temperature Shape Memory Alloy

2017 ◽  
Vol 898 ◽  
pp. 598-603
Author(s):  
Jun Li ◽  
Xiao Yang Yi ◽  
Wei Hong Gao ◽  
Wen Long Song ◽  
Xiang Long Meng
Keyword(s):  
High Temperature ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Memory Effect ◽  
Thermal Cycle ◽  
Thermal Cycles ◽  
Solution Treated ◽  
Temperature Memory Effect ◽  
Lower Temperature ◽  
Complete Transformation

Temperature memory effect in the solution-treated Ti-Ni-Hf-Y high temperature shape memory alloy (HTSMA) was investigated. The results showed that the temperature memory effect induced by the partial cycling could be detected in the subsequent complete transformation cycling for the solution-treated Ti-Ni-Hf-Y alloy. The temperature memory effect is one-time phenomenon. However, the temperature memory effect could last at least 20 times when the sample was employed 10 times complete thermal cycles. Multiple-steps temperaure memory effect can be observed as the sample undergoes the lower temperature partial thermal cycle in sequence. The mechanisms of the temperature memory effect were discussed in this paper.

A novel robot hand with embedded shape memory alloy actuators

2002 ◽  
Vol 216 (7) ◽  
pp. 737-745 ◽  
Author(s):  
K Yang ◽  
C L Gu
Keyword(s):  
Mechanical Properties ◽  
Control System ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Outer Diameter ◽  
Robot Hand ◽  
Sma Actuators ◽  
Constant Distance

This paper describes the development of an active robot hand, which allows smooth and lifelike motions for anthropomorphic grasping and fine manipulations. An active robot finger 10mm in outer diameter with a shape memory alloy (SMA) wire actuator embedded in the finger with a constant distance from the geometric centre of the finger was designed and fabricated. The practical specifications of the SMA wire and the flexible rod were determined on the basis of a series of formulae. The active finger consists of two bending parts, the SMA actuators and a connecting part. The mechanical properties of the bending part are investigated. The control system on the base of resistance feedback is also presented. Finally, a robot hand with three fingers was designed and the grasping experiment was carried out to demonstrate its performance.

Sign in / Sign up

Export Citation Format

Share Document