Structure Evaluation of Compact Force Sensor Using Shape-memory Polymer

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.

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C112 Study on force sensor using shape-memory polymer sheet with embedded electrical heating wire

The Proceedings of the JSME Conference on Frontiers in Bioengineering ◽

10.1299/jsmebiofro.2014.25.81 ◽

2014 ◽

Vol 2014.25 (0) ◽

pp. 81-82

Author(s):

Hiroki KAMIZONO ◽

Kazuto TAKASHIMA ◽

Makoto TAKENAKA ◽

Toshiharu MUKAI

Keyword(s):

Shape Memory ◽

Shape Memory Polymer ◽

Force Sensor ◽

Electrical Heating ◽

Polymer Sheet ◽

Heating Wire

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

ROBOMECH Journal ◽

10.1186/s40648-021-00210-8 ◽

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.

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Electrical and thermal stimuli responsive thermoplastic shape memory polymer composites containing rGO, Fe3O4 and rGO–Fe3O4 fillers

Polymer Bulletin ◽

10.1007/s00289-020-03427-6 ◽

2020 ◽

Author(s):

G. Jerald Maria Antony ◽

S. T. Aruna ◽

Chetan S. Jarali ◽

S. Raja

Keyword(s):

Shape Memory ◽

Polymer Composites ◽

Shape Memory Polymer ◽

Stimuli Responsive ◽

Thermal Stimuli

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Design of Shape Memory Thermoplastic Material Systems for FDM-Type Additive Manufacturing

Materials ◽

10.3390/ma14154254 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4254

Author(s):

Paulina A. Quiñonez ◽

Leticia Ugarte-Sanchez ◽

Diego Bermudez ◽

Paulina Chinolla ◽

Rhyan Dueck ◽

...

Keyword(s):

Additive Manufacturing ◽

Shape Memory ◽

Thermomechanical Processing ◽

Material Selection ◽

Shape Memory Polymer ◽

Fused Filament Fabrication ◽

Materials Development ◽

Thermoplastic Material ◽

Polymer Systems ◽

Injection Molded

The work presented here describes a paradigm for the design of materials for additive manufacturing platforms based on taking advantage of unique physical properties imparted upon the material by the fabrication process. We sought to further investigate past work with binary shape memory polymer blends, which indicated that phase texturization caused by the fused filament fabrication (FFF) process enhanced shape memory properties. In this work, two multi-constituent shape memory polymer systems were developed where the miscibility parameter was the guide in material selection. A comparison with injection molded specimens was also carried out to further investigate the ability of the FFF process to enable enhanced shape memory characteristics as compared to other manufacturing methods. It was found that blend combinations with more closely matching miscibility parameters were more apt at yielding reliable shape memory polymer systems. However, when miscibility parameters differed, a pathway towards the creation of shape memory polymer systems capable of maintaining more than one temporary shape at a time was potentially realized. Additional aspects related to impact modifying of rigid thermoplastics as well as thermomechanical processing on induced crystallinity are also explored. Overall, this work serves as another example in the advancement of additive manufacturing via materials development.

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Autonomous Off‐Equilibrium Morphing Pathways of a Supramolecular Shape‐Memory Polymer

Advanced Materials ◽

10.1002/adma.202102473 ◽

2021 ◽

pp. 2102473

Author(s):

Wenjun Peng ◽

Guogao Zhang ◽

Qian Zhao ◽

Tao Xie

Keyword(s):

Shape Memory ◽

Shape Memory Polymer

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Pressure Orientation-Dependent Recovery of 3D-Printed PLA Objects with Varying Infill Degree

Polymers ◽

10.3390/polym13081275 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1275 ◽

Cited By ~ 1

Author(s):

Guido Ehrmann ◽

Andrea Ehrmann

Keyword(s):

Shape Memory ◽

Fused Deposition Modeling ◽

Static Load ◽

Shape Memory Polymer ◽

Applied Pressure ◽

Poly Lactic Acid ◽

Fused Deposition ◽

Deposition Modeling ◽

Load Tests ◽

3D Printed

Poly(lactic acid) is not only one of the most often used materials for 3D printing via fused deposition modeling (FDM), but also a shape-memory polymer. This means that objects printed from PLA can, to a certain extent, be deformed and regenerate their original shape automatically when they are heated to a moderate temperature of about 60–100 °C. It is important to note that pure PLA cannot restore broken bonds, so that it is necessary to find structures which can take up large forces by deformation without full breaks. Here we report on the continuation of previous tests on 3D-printed cubes with different infill patterns and degrees, now investigating the influence of the orientation of the applied pressure on the recovery properties. We find that for the applied gyroid pattern, indentation on the front parallel to the layers gives the worst recovery due to nearly full layer separation, while indentation on the front perpendicular to the layers or diagonal gives significantly better results. Pressing from the top, either diagonal or parallel to an edge, interestingly leads to a different residual strain than pressing from front, with indentation on top always firstly leading to an expansion towards the indenter after the first few quasi-static load tests. To quantitatively evaluate these results, new measures are suggested which could be adopted by other groups working on shape-memory polymers.

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Harnessing reversible dry adhesion using shape memory polymer microparticles

RSC Advances ◽

10.1039/d1ra01473k ◽

2021 ◽

Vol 11 (32) ◽

pp. 19616-19622

Author(s):

Wenbing Li ◽

Junhao Liu ◽

Wanting Wei ◽

Kun Qian

Keyword(s):

Shape Memory ◽

Shape Memory Polymer ◽

Shape Memory Polymers ◽

Memory Effects ◽

Reversible Adhesion ◽

Dry Adhesion ◽

Bonding Property ◽

Shape Memory Effects ◽

Polymer Microparticles

Shape memory polymers can provide excellent bonding property because of their shape memory effects. This paper proposes an adhesive unit that is capable of repeatable smart adhesion and exhibits reversible adhesion under heating.

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