In-situ Performance Evaluation of Large Shape Memory Polymer Components via Distributed Optical Fibre Sensors

The paper discusses the possibility of using in situ generated hybrid polymer-polymer nanocomposites as polymeric materials with triple shape memory, which, unlike conventional polymer blends with triple shape memory, are characterized by fully separated phase transition temperatures and strongest bonding between the polymer blends phase interfaces which are critical to the shape fixing and recovery. This was demonstrated using the three-component system polylactide/polybutylene adipateterephthalate/cellulose nanofibers (PLA/PBAT/CNFs). The role of in situ generated PBAT nanofibers and CNFs in the formation of efficient physical crosslinks at PLA-PBAT, PLA-CNF and PBAT-CNF interfaces and the effect of CNFs on the PBAT fibrillation and crystallization processes were elucidated. The in situ generated composites showed drastically higher values of strain recovery ratios, strain fixity ratios, faster recovery rate and better mechanical properties compared to the blend.

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Remote, selective, and in situ manipulation of liquid droplets on a femtosecond laser-structured superhydrophobic shape-memory polymer by near-infrared light

Science China Chemistry ◽

10.1007/s11426-020-9940-6 ◽

2021 ◽

Author(s):

Xue Bai ◽

Jiale Yong ◽

Chao Shan ◽

Yao Fang ◽

Xun Hou ◽

...

Keyword(s):

Femtosecond Laser ◽

Shape Memory ◽

Near Infrared ◽

Shape Memory Polymer ◽

Infrared Light ◽

Liquid Droplets ◽

Near Infrared Light

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In Situ Reversible Tuning from Pinned to Roll-Down Superhydrophobic States on a Thermal-Responsive Shape Memory Polymer by a Silver Nanowire Film

ACS Applied Materials & Interfaces ◽

10.1021/acsami.9b20223 ◽

2020 ◽

Vol 12 (11) ◽

pp. 13464-13472 ◽

Cited By ~ 4

Author(s):

Chuanzong Li ◽

Yunlong Jiao ◽

Xiaodong Lv ◽

Sizhu Wu ◽

Chao Chen ◽

...

Keyword(s):

Shape Memory ◽

Shape Memory Polymer ◽

Silver Nanowire

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Shape Memory Polymer Based Reconfigurable Compliant Mechanisms: An Exploration

Volume 7: 33rd Mechanisms and Robotics Conference, Parts A and B ◽

10.1115/detc2009-87331 ◽

2009 ◽

Author(s):

Nilesh D. Mankame ◽

Alan L. Browne ◽

Anupam Saxena

Keyword(s):

Shape Memory ◽

High Temperatures ◽

Compliant Mechanisms ◽

Shape Memory Polymer ◽

Shape Memory Polymers ◽

Large Strains ◽

Qualitative And Quantitative ◽

Order Of Magnitude ◽

Quantitative Changes

This paper explores the concept of reconfigurable compliant mechanisms. We define these to be fully or partially compliant mechanisms whose performance can be modified after they have been fabricated. Specifically, we are interested in the nature and extent of in situ reconfigurability in compliant mechanisms. In other words, we seek to understand the range of performance that can be achieved by these mechanisms without requiring significant reassembly. The material properties such as the storage modulus of a newly studied class of materials — shape memory polymers — vary by over an order of magnitude over a temperature range of 20 – 50 C. These polymers also allow the fixing of moderate to large strains (20 – 75%) experienced at high temperatures for extended periods of time, while retaining the ability to remember their original shape when reheated to the same high temperatures. These two properties make shape memory polymers a natural candidate for the fabrication of reconfigurable compliant mechanisms. We explore various means for introducing reconfigurability in compliant mechanisms, and from these, select a subset that is suitable for in situ reconfiguration. Quasi-static nonlinear finite element simulations are used to study the change in performance due to reconfiguration of four fully compliant mechanisms made of a shape memory polymer. Preliminary results indicate that noticeable qualitative and quantitative changes in performance can be achieved by these mechanisms.

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Current-Dependent Kinetics of Self-Folding for Multi-Layer Polymers Using Local Resistive Heating

Volume 2: Materials; Joint MSEC-NAMRC-Manufacturing USA ◽

10.1115/msec2018-6628 ◽

2018 ◽

Author(s):

Moataz Elsisy ◽

Evan Poska ◽

Mostafa Bedewy

Keyword(s):

Temperature Gradient ◽

Shape Memory ◽

Material Flow ◽

Shape Memory Polymer ◽

Lightweight Structures ◽

Local Material ◽

Flow Heat ◽

Origami Engineering ◽

Kinetics Of

The purpose of this paper is to characterize the kinetics and direction of self-folding of pre-strained polystyrene (PSPS) and non-pre-strained styrene (NPS), which results from local shrinkage using a resistively heated ribbon in contact with the polymer sheet. A temperature gradient across the thickness of this shape memory polymer (SMP) sheet induces folding along the line of contact with the heating ribbon. Varying the electric current changes the degree of folding and extent of local material flow. This method can be used to create practical 3D structures. Sheets of PSPS and NPS were cut to 10 × 20 mm samples and their folding angles were plotted with respect to time, as obtained from in situ videography. In addition, the use of polyimide tape (Kapton) was investigated for controlling the direction of self-folding. Results show that folding happens on the opposite side of the sample with respect to the tape, regardless of which side the heating ribbon is on, or whether gravity is opposing the folding direction. Given the tunability of fold times and extent of local material flow, heat-assisted folding is a promising approach for manufacturing complex 3D lightweight structures by origami engineering.

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