scholarly journals The Influence of Shape Changing Behaviors from 4D Printing through Material Extrusion Print Patterns and Infill Densities

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3754
Author(s):  
Seokwoo Nam ◽  
Eujin Pei
Keyword(s):  
Shape Memory ◽  
Recovery Time ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Material Extrusion ◽  
Concentric Pattern ◽  
Dimensional Printing ◽  
Recovery Result ◽  
Am Processes ◽  
Recovery Temperature

Four-dimensional printing (4DP) is an approach of using Shape Memory Materials (SMMs) with additive manufacturing (AM) processes to produce printed parts that can deform over a determined amount of time. This research examines how Polylactic Acid (PLA), as a Shape Memory Polymer (SMP), can be programmed by manipulating the build parameters of material extrusion. In this research, a water bath experiment was used to show the results of the shape-recovery of bending and shape-recovery speed of the printed parts, according to the influence of the print pattern, infill density and recovery temperature (Tr). In terms of the influence of the print pattern, the ‘Quarter-cubic’ pattern with a 100% infill density showed the best recovery result; and the ‘Line’ pattern with a 20% infill density showed the worst recovery result. The ‘Cubic-subdivision’ pattern with a 20% infill density demonstrated the shortest recovery time; and the ‘Concentric’ pattern with a 100% infill density demonstrated the longest recovery time. The results also showed that a high temperature and high infill density provided better recovery, and a low temperature and low infill density resulted in poor recovery.

Manufacturing of a Shape Memory Polymer Actuator

2015 ◽  
Author(s):  
Loredana Santo ◽  
Giovanni Matteo Tedde ◽  
Fabrizio Quadrini
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Active Element ◽  
Shape Memory Polymer ◽  
Applied Pressure ◽  
Maximum Load ◽  
Medium Size ◽  
Cylindrical Shape ◽  
Polymer Actuator ◽  
Recovery Temperature

Shape memory polymer (SMP) foams can be used to manufacture actuators with tailored actuation rate. Being related to foam shape recovery by heating, SMP actuator operates by conversion of heat into motion. In the current study, a SMP linear actuator has been manufactured which is able to apply a maximum load of 50 N (depending on the recovery temperature) and a maximum stroke up to 30 mm. The actuator had a cylindrical shape and its piston had a diameter of 16 mm, therefore a maximum applied pressure about 2.5 bar. The active element (i.e. SMP foam) was produced by solid state foaming of an epoxy resin, and its shaping was performed in the same metallic frame of the actuator. Results show that small and medium-size actuators can be easily produced and operated.

Functional Fatigue of Shape-Memory Polymers

2009 ◽  
Vol 1190 ◽  
Author(s):  
Christina Schmidt ◽  
Klaus Neuking ◽  
Gunther Eggeler
Keyword(s):  
Critical Temperature ◽  
Shape Memory ◽  
Recovery Time ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Fatigue Behaviour ◽  
Model Material ◽  
Functional Fatigue ◽  
Irreversible Strain ◽  
Recovery Temperature

AbstractThe present study represents a first step towards an understanding of what we refer to as the functional fatigue behaviour of shape-memory polymers. These materials have a processing shape B and a programmed shape A [1]. And when the material is exposed to an appropriate stimulus (in our case: heating above a critical temperature), a one way effect is observed: A → B (one way effect: 1WE). The objectives of the present study were to find out whether and how often programming can be repeated, whether repeated programming affects the 1WE and how much irreversible strain the material accumulates. We study the effect in dependence of different stress levels, and consider the effect of recovery temperature and recovery time. As a model material we examine the commercial amorphous shape-memory polymer Tecoflex® and subject it to 50 programming/1WE cycles. It turns out that programming, cooling, unloading and heating to trigger the 1WE causes an increase of irreversible strain and is associated with a corresponding decrease of the intensity of the 1WE in particular during the first thermomechanical cycles. 1. M. Behl and A. Lendlein, materials today 10, 20 (2007).

Investigate of Electrical Conductivity of Shape-Memory Polymer Filled with Carbon Black

2008 ◽  
Vol 47-50 ◽  
pp. 714-717 ◽  
Author(s):  
Xin Lan ◽  
Jin Song Leng ◽  
Yan Ju Liu ◽  
Shan Yi Du
Keyword(s):  
Electrical Conductivity ◽  
Carbon Black ◽  
Shape Memory ◽  
Shape Recovery ◽  
Volume Fraction ◽  
Shape Memory Polymer ◽  
Recovery Process ◽  
Thermomechanical Properties ◽  
Electrically Conductive ◽  
New System

A new system of thermoset styrene-based shape-memory polymer (SMP) filled with carbon black (CB) is investigated. To realize the electroactive stimuli of SMP, the electrical conductivity of SMP filled with various amounts of CB is characterized. The percolation threshold of electrically conductive SMP filled with CB is about 3% (volume fraction of CB), which is much lower than many other electrically conductive polymers. When applying a voltage of 30V, the shape recovery process of SMP/CB(10 vol%) can be realized in about 100s. In addition, the thermomechanical properties are also characterized by differential scanning calorimetery (DSC).

scholarly journals Electrical actuation and shape recovery control of shape-memory polymer nanocomposites

2013 ◽  
Vol 4 (3) ◽  
pp. 167-178 ◽  
Author(s):  
Fei Liang ◽  
Robert Sivilli ◽  
Jihua Gou ◽  
Yunjun Xu ◽  
Bob Mabbott
Keyword(s):  
Shape Memory ◽  
Polymer Nanocomposites ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Electrical Actuation

An investigation into the effect of thermal variables on the 3D printed shape memory polymer structures with different geometries

2021 ◽  
pp. 1045389X2110282
Author(s):  
Mohammadhadi Hosseinzadeh ◽  
Majid Ghoreishi ◽  
Keivan Narooei
Keyword(s):  
Optimum Condition ◽  
Heating Rate ◽  
Deformation Temperature ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Mechanical Tests ◽  
Thermal Parameters ◽  
Three Point Bending ◽  
Recovery Temperature ◽  
Rounded Rectangle

In this paper, the effects of thermal parameters including the deformation temperature, shape recovery temperature, and heating rate on the shape recovery of a specific rounded rectangle structure were investigated using the design of experiments. Three-point bending thermo-mechanical tests were subsequently carried out where water was used for controlling the temperature. It was found that the deformation temperature and heating rate have the most and the least effect on the shape recovery of polylactic acid (PLA) SMPs, respectively. The mathematical modeling results showed that the optimum condition of the highest shape recovery is obtained at the deformation temperature of 53.31°C, recovery temperature of 59.94°C, and heating rate of 8.05°C/min. It was also observed that the shape recovery of the specified rounded rectangle structure manufactured by the 3D printing method was enhanced from 93.03% to 98.14% by optimizing the thermal parameters. Besides, the optimum condition was applied to structures with different cell geometries and it was shown that the obtained condition was also enhanced the shape recovery of structures with diamond and honeycomb. More specifically, the shape recovery of noted structures was significantly enhanced to 98.00% and 97.71 % from 82.86% and 78.89%, respectively.

Characristics of Shape Memory Composites Combined with Shape Memory Alloy and Shape Memory Polymer

2013 ◽  
Vol 705 ◽  
pp. 169-172
Author(s):  
Xue Feng ◽  
Li Min Zhao ◽  
Xu Jun Mi
Keyword(s):  
Shape Memory ◽  
Room Temperature ◽  
Shape Recovery ◽  
Volume Fraction ◽  
Shape Memory Polymer ◽  
Young Modulus ◽  
Thermomechanical Properties ◽  
The Matrix ◽  
Shape Memory Composites ◽  
Shape Fixity

In order to develop high functionality of shape memory materials, the shape memory composites combined with TiNi wire and shape memory epoxy were prepared, and the mechanical and thermomechanical properties were studied. The results showed the addition of TiNi wire increased the Young modulus and breaking strength both at room temperature and at elevated temperature. The composites maintained the rates of shape fixity and shape recovery close to 100%. The maximum recovery stress increased with increasing TiNi wire volume fraction, and obtained almost 3 times of the matrix by adding 1vol% TiNi wire.

Origami-inspired shape memory dual-matrix composite structures

2019 ◽  
Vol 30 (17) ◽  
pp. 2639-2647
Author(s):  
O-Hyun Kwon ◽  
Jin-Ho Roh
Keyword(s):  
Shape Memory ◽  
Polymer Composite ◽  
Matrix Composite ◽  
Composite Structures ◽  
Shape Recovery ◽  
Shape Memory Polymer ◽  
Tensile Tests ◽  
Woven Fabrics ◽  
Morphing Structure ◽  
Composite Skins

A sandwiched morphing structure is developed using an Origami-inspired shape memory dual-matrix composite core and shape memory polymer composite skins. The geometric parameters of the morphing structure are designed to have a zero Poisson’s ratio. In addition, an analytical model is developed to analyze the three-dimensional morphing structure easily. The shape memory dual-matrix composites are fabricated with woven fabrics based on the shape memory polymers, and an epoxy matrix is used to ensure a flexible and shape-recoverable structure. The shape recoverability of the shape memory polymer composite skins is verified by measuring the shape recovery ratio at various temperatures. Based on the tensile tests for the shape memory polymer composite skins and shape memory polymer hinges, it is found that the morphing structure can be highly flexible depending on temperature. Finally, the bending and shape recovery behaviors of the morphing structure are demonstrated.

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