scholarly journals Characterization of variable-sensitivity force sensor using stiffness change of shape-memory polymer based on temperature

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Kazuto Takashima ◽  
Jo Kobuchi ◽  
Norihiro Kamamichi ◽  
Kentaro Takagi ◽  
Toshiharu Mukai
Keyword(s):  
Transfer Function ◽  
Shape Memory ◽  
Force Measurement ◽  
Shape Memory Polymer ◽  
Viscoelastic Behavior ◽  
Force Sensor ◽  
Measurement Range ◽  
Applied Force ◽  
Soft Phase ◽  
Variable Sensitivity

AbstractIn the present study, we propose a variable-sensitivity force sensor using a shape-memory polymer (SMP), the stiffness of which varies according to the temperature. Since the measurement range and sensitivity can be changed, it is not necessary to replace the force sensor to match the measurement target. Shape-memory polymers are often described as two-phase structures comprising a lower-temperature “glassy” hard phase and a higher-temperature “rubbery” soft phase. The relationship between the applied force and the deformation of the SMP changes depending on the temperature. The proposed sensor consists of strain gauges bonded to an SMP bending beam and senses the applied force by measuring the strain. Therefore, the force measurement range and the sensitivity can be changed according to the temperature. In our previous study, we found that a sensor with one strain gauge and a steel plate had a small error and a large sensitivity range. Therefore, in the present study, we miniaturize this type of sensor. Moreover, in order to describe the viscoelastic behavior more accurately, we propose a transfer function using a generalized Maxwell model. We verify the proposed model experimentally and estimated the parameters by system identification. In addition, we realize miniaturization of the sensor and achieve the same performance as in our previous study. It is shown that the proposed transfer function can capture the viscoelastic behavior of the proposed SMP sensor quite well.

scholarly journals Characterization of Variable-sensitivity Compact Force Sensor using Stiffness Change of Shape-memory Polymer Based on Temperature

2021 ◽  
Author(s):  
Kazuto Takashima ◽  
Jo Kobuchi ◽  
Norihiro Kamamichi ◽  
Kentaro Takagi ◽  
Toshiharu Mukai
Keyword(s):  
Transfer Function ◽  
Shape Memory ◽  
Force Measurement ◽  
Shape Memory Polymer ◽  
Viscoelastic Behavior ◽  
Force Sensor ◽  
Measurement Range ◽  
Applied Force ◽  
Soft Phase ◽  
Variable Sensitivity

Abstract In the present study, we propose a variable-sensitivity force sensor using a shape-memory polymer (SMP), the stiffness of which varies according to the temperature. Since the measurement range and sensitivity can be changed, it is not necessary to replace the force sensor to match the measurement target. Shape-memory polymers are often described as two-phase structures comprising a lower-temperature “glassy” hard phase and a higher-temperature “rubbery” soft phase. The relationship between the applied force and the deformation of the SMP changes depending on the temperature. The proposed sensor consists of strain gauges bonded to an SMP bending beam and senses the applied force by measuring the strain. Therefore, the force measurement range and the sensitivity can be changed according to the temperature. In our previous study, we found that a sensor with one strain gauge and a steel plate had a small error and a large sensitivity range. Therefore, in the present study, we miniaturize this type of sensor. Moreover, in order to describe the viscoelastic behavior more accurately, we propose a transfer function using a generalized Maxwell model. We verify the proposed model experimentally and estimated the parameters by system identification. In addition, we realize miniaturization of the sensor and achieve the same performance as in our previous study. It is shown that the proposed transfer function can capture the viscoelastic behavior of the proposed SMP sensor quite well.

Blocking force measurement of shape memory polymer composite hinges for space deployable structures

2018 ◽  
Vol 29 (18) ◽  
pp. 3667-3678 ◽  
Author(s):  
Thanh Duc Dao ◽  
Nam Seo Goo ◽  
Woong Ryeol Yu
Keyword(s):  
Shape Memory ◽  
Polymer Composite ◽  
Mechanical Performance ◽  
Force Measurement ◽  
Shape Change ◽  
Shape Memory Polymer ◽  
Mass System ◽  
Manufacturing Method ◽  
Moment Arms ◽  
Repeated Test

This study introduces a method for measuring the blocking force of a shape memory polymer composite hinge to quantify the performance of a shape memory polymer composite hinge for space deployable structure applications. A detailed design of how to select heating elements for a self-deployable configuration is also suggested. The shape memory polymer composite hinge consists of two reverse carpenter shape memory polymer composite tapes that were made from carbon-epoxy fabric, shape memory polymer resin, and two heating elements. The heating elements were attached to the shape memory polymer composite tape using the composite manufacturing method, and they were used as the heating source in the deployment test. The blocking force and moment of the hinge were measured using a pulley–mass system setup to examine the mechanical performance of the hinge. During the test, the shape change was recorded with a camera to calculate the moment arms. While the blocking force was 7.21 N in the initial test, it decreased slightly with the working cycle and was 6.27 N in the repeated test. The maximum hinge moment was 0.47 N m in the repeated test. In addition, the results revealed that a pop-up phenomenon occurred at the middle period of deployment. These results confirm that the shape memory polymer composite hinge works well with heating elements and provide a guideline for performance evaluation of the shape memory polymer composite hinge.

New Giant Magnetostrictive Force Sensors

2013 ◽  
Vol 816-817 ◽  
pp. 424-428
Author(s):  
Rong Ge Yan ◽  
Li Hua Zhu ◽  
Qing Xin Yang
Keyword(s):  
Force Measurement ◽  
Force Sensor ◽  
Measurement Range ◽  
Magnetic Flux Density ◽  
Force Sensors ◽  
Dynamic Force ◽  
Element Analysis ◽  
Giant Magnetostrictive Materials ◽  
Overload Capacity ◽  
Adjustable Range

Force sensors, based on the giant inverse magnetostrictive effect, have a series of outstanding properties, such as large overload capacity, which make them have more and more applications to the field of automatic control system of heavy industry, chemical industry. This paper designs new giant magnetostrictive force sensors using the rare-earth iron giant magnetostrictive materials. With the designed giant magnetostrictive force sensor, the relations between magnetic flux density in the gap and applied static stress on the sensor, the inductive voltage in the coil and time (with the dynamic stress), are calculated by finite element analysis software. The related confirmatory experiments have been conducted. The experimental results indicate that the giant magnetostrictive force sensor is fit for static and dynamic force measurement. In order to enlarge the measurement range, the designed force sensor as the basic cell is combined. This paper gives two kinds of combinations, which have the feature of adjustable range.

scholarly journals A Disturbance Suppression Micro-Newton Force Sensor Based on Shadow Method

2022 ◽  
Author(s):  
Yong Yang ◽  
Meirong Zhao ◽  
Dantong Li ◽  
Moran Tao ◽  
Chunyuan Zhu ◽  
...  
Keyword(s):  
Normal Force ◽  
Vibrational Energy ◽  
Force Measurement ◽  
Damping Ratio ◽  
Force Sensor ◽  
Measurement Range ◽  
Complex Environments ◽  
Shadow Method ◽  
Reliable Measurement ◽  
Flat Punch

<div>The precision of micro-force measurement is determined by the sensitivity of force sensors and the magnitude of environmental disturbances. Damping, a process that converts vibrational energy into heat, is one of the most effective methods of suppressing disturbances. Inspired by the shadow formed at a pond when water striders walked on the water, a bionic viscoelastic-polymer micro-force (VPMF) sensor with a high damping ratio based on the shadow method was developed. In the VPMF sensor, the surface of the polymer was deformed by the contact of a cylindrical flat punch when the sensor was subjected to a normal force. A shadow with a bright edge was formed due to the refraction that parallel light went through the deformed surface. The force was in proportion to the change of the shadow diameter. The sensor optimal sensitivity was 2.15 μN/pixel and the measurement range was 0.981 mN. The damping ratio of the VPMF sensor was 0.22 on account of viscoelasticity, which could suppress disturbances effectively. The VPMF sensor could reduce the influence of disturbances by about 96.23% compared to the cantilever. The present study suggests that the VPMF sensor is hopefully applied to the reliable measurement of micro force under complex environments.</div>

scholarly journals Force sensor utilizing stiffness change of shape-memory polymer based on temperature

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Kazuto Takashima ◽  
Hiroki Kamizono ◽  
Makoto Takenaka ◽  
Toshiharu Mukai
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Force Sensor

Review on Biomechanical Simulation, Measurement and Control of Orthodontic Force

2013 ◽  
Vol 647 ◽  
pp. 623-629
Author(s):  
Yun Feng Liu ◽  
Gen Zhou ◽  
Sean Shih Yao Liu
Keyword(s):  
Shape Memory ◽  
Force Measurement ◽  
Treatment Plan ◽  
Shape Memory Polymer ◽  
Orthodontic Force ◽  
Construction Methods ◽  
Biomechanical Simulation ◽  
Constitute Model ◽  
And Control ◽  
Measurement And Control

The forces and moments supplied by braces determine the movement of tooth in orthodontic treatment, so clearly quantifying the force value is very important to formulate precise treatment plan. In recent decades, scholars have presented many articles about biomechanical research on orthodontic force. Based on investigations of these papers, techniques on orthodontic force stimulation including oral model (bone, PDL and teeth included) reconstruction and constitute model construction, methods in orthodontic force measurement including physical oral model fabrication and device architectures, and techniques on orthodontic force control such as the use of shape memory alloy and shape memory polymer as the wire material, are reviewed. At the end, the conclusions and future works are given.

Experimental Investigations on Viscoelastic Properties of a Shape Memory Polymer

2014 ◽  
Author(s):  
Pauline Butaud ◽  
Morvan Ouisse ◽  
Vincent Placet ◽  
Emmanuel Foltête
Keyword(s):  
Shape Memory ◽  
Smart Materials ◽  
Viscoelastic Properties ◽  
Mechanical Characterization ◽  
Shape Memory Polymer ◽  
Viscoelastic Behavior ◽  
Experimental Investigations ◽  
Special Focus ◽  
Suitable Model ◽  
Resonance Frequencies

The shape memory polymers (SMPs) are polymeric smart materials which have the remarkable ability to recover their primary shape from a temporary one under an external stimulus. The study deals with the synthesis and the thermo-mechanical characterization of a thermally-actuated SMP, the tBA/PEGDMA, with a special focus on viscoelastic properties. The mechanical characterization is performed using three kinds of tests: quasi-static tensile tests, dynamic mechanical analysis (DMA) and modal tests. The first one allows the identification of the Youngs modulus and the Poisson’s ratio at ambient temperature. Modal analyses are done for various temperature values, and resonance frequencies are measured. In order to validate the time-temperature equivalence on this SMP, a DMA is performed under harmonic loading for different temperatures and a master curve highlights a complementarity of the results. Finally a suitable model for the viscoelastic behavior of the SMP is identified.

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