scholarly journals Chemical Modifications of Porous Shape Memory Polymers for Enhanced X-ray and MRI Visibility

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4660
Author(s):  
Grace K. Fletcher ◽  
Landon D. Nash ◽  
Lance M. Graul ◽  
Lindy K. Jang ◽  
Scott M. Herting ◽  
...  
Keyword(s):  
Shape Memory ◽  
Medical Devices ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Tissue Scaffolds ◽  
Resonance Imaging ◽  
Clinical Imaging ◽  
X Ray ◽  
Device Development ◽  
Magnetic Resonance Imaging Mri

The goal of this work was to develop a shape memory polymer (SMP) foam with visibility under both X-ray and magnetic resonance imaging (MRI) modalities. A porous polymeric material with these properties is desirable in medical device development for applications requiring thermoresponsive tissue scaffolds with clinical imaging capabilities. Dual modality visibility was achieved by chemically incorporating monomers with X-ray visible iodine-motifs and MRI visible monomers with gadolinium content. Physical and thermomechanical characterization showed the effect of increased gadopentetic acid (GPA) on shape memory behavior. Multiple compositions showed brightening effects in pilot, T1-weighted MR imaging. There was a correlation between the polymeric density and X-ray visibility on expanded and compressed SMP foams. Additionally, extractions and indirect cytocompatibility studies were performed to address toxicity concerns of gadolinium-based contrast agents (GBCAs). This material platform has the potential to be used in a variety of medical devices.

scholarly journals Harnessing reversible dry adhesion using shape memory polymer microparticles

RSC Advances ◽  
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.

scholarly journals Structural multi-colour invisible inks with submicron 4D printing of shape memory polymers

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wang Zhang ◽  
Hao Wang ◽  
Hongtao Wang ◽  
John You En Chan ◽  
Hailong Liu ◽  
...  
Keyword(s):  
Shape Memory ◽  
Information Hiding ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Photonic Devices ◽  
Temperature Sensitive ◽  
4D Printing ◽  
Two Photon ◽  
Shape Memory Effects ◽  
Nanoscale Structure

AbstractFour-dimensional (4D) printing of shape memory polymer (SMP) imparts time responsive properties to 3D structures. Here, we explore 4D printing of a SMP in the submicron length scale, extending its applications to nanophononics. We report a new SMP photoresist based on Vero Clear achieving print features at a resolution of ~300 nm half pitch using two-photon polymerization lithography (TPL). Prints consisting of grids with size-tunable multi-colours enabled the study of shape memory effects to achieve large visual shifts through nanoscale structure deformation. As the nanostructures are flattened, the colours and printed information become invisible. Remarkably, the shape memory effect recovers the original surface morphology of the nanostructures along with its structural colour within seconds of heating above its glass transition temperature. The high-resolution printing and excellent reversibility in both microtopography and optical properties promises a platform for temperature-sensitive labels, information hiding for anti-counterfeiting, and tunable photonic devices.

Structural tuning of polycaprolactone based thermadapt shape memory polymer

2020 ◽  
Vol 11 (7) ◽  
pp. 1369-1374 ◽  
Author(s):  
Wusha Miao ◽  
Weike Zou ◽  
Yingwu Luo ◽  
Ning Zheng ◽  
Qiao Zhao ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Controlled Structures

Polycaprolactone based thermadapt shape memory polymers with precisely controlled structures allow tunable shape reconfigurability.

scholarly journals The Assessment of the Condition of Knee Joint Surfaces with Acoustic Emission Analysis

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6495
Author(s):  
Bartłomiej Sawaryn ◽  
Natalia Piaseczna ◽  
Szymon Sieciński ◽  
Rafał Doniec ◽  
Konrad Duraj ◽  
...  
Keyword(s):  
Knee Joint ◽  
Knee Injury ◽  
Knee Joints ◽  
Resonance Imaging ◽  
Emission Analysis ◽  
X Ray ◽  
Joint Surfaces ◽  
Magnetic Resonance Imaging Mri ◽  
Leg Movements ◽  
Acoustic Emission Analysis

The knee joint, being the largest joint in the human body, is responsible for a great percentage of leg movements. The diagnosis of the state of knee joints is usually based on X-ray scan, ultrasound imaging, computerized tomography (CT), magnetic resonance imaging (MRI), or arthroscopy. In this study, we aimed to create an inexpensive, portable device for recording the sound produced by the knee joint, and a dedicated application for its analysis. During the study, we examined fourteen volunteers of different ages, including those who had a knee injury. The device effectively enables the recording of the sounds produced by the knee joint, and the spectral analysis used in the application proved its reliability in evaluating the knee joint condition.

Shape-Memory Polymer Medical Devices

2019 ◽  
pp. 394-405
Author(s):  
Muhammad Y. Razzaq ◽  
Markus Reinthaler ◽  
Mark Schröder ◽  
Christian Wischke ◽  
Andreas Lendlein
Keyword(s):  
Shape Memory ◽  
Medical Devices ◽  
Shape Memory Polymer

scholarly journals Carcinomatous encephalitis as clinical presentation of occult lung adenocarcinoma: case report

2007 ◽  
Vol 65 (3b) ◽  
pp. 841-844 ◽  
Author(s):  
Henrique Barbosa Ribeiro ◽  
Tadeu Ferreira de Paiva Jr ◽  
Gustavo Pignatari Rosas Mamprin ◽  
Milton Luiz Gorzoni ◽  
Antônio José da Rocha ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Computed Tomography ◽  
Clinical Presentation ◽  
Clinical Manifestations ◽  
Mass Effect ◽  
Pulmonary Adenocarcinoma ◽  
Rare Entity ◽  
Resonance Imaging ◽  
Clinical Imaging ◽  
Magnetic Resonance Imaging Mri

Carcinomatous encephalitis is a rare entity, originally described by Madow and Alpers in 1951, which is characterized by tumoral spreading perivascular, without mass effect. Clinical manifestations such as hemiparesis, seizures, ataxia, speech difficulties, cerebrospinal fluid findings as well as computed tomography are nonspecific. This leads the physician to pursue more frequent diseases that could explain those manifestations - toxic, metabolic, and/or infectious encephalopathy. A magnetic resonance imaging (MRI) with gadolinium, the method of choice, presumes the diagnosis. Previous reports of this unusual form of metastatic disease have described patients with prior diagnosis of pulmonary adenocarcinoma. We present the case of carcinomatous encephalitis in a 76-years-old woman as the primary manifestation of occult pulmonary adenocarcinoma with its clinical, imaging, and anatomopathological findings.

scholarly journals Increased X-ray Visualization of Shape Memory Polymer Foams by Chemical Incorporation of Iodine Motifs

Polymers ◽  
2017 ◽  
Vol 9 (12) ◽  
pp. 381 ◽  
Author(s):  
Landon Nash ◽  
Mary Browning Monroe ◽  
Yong-Hong Ding ◽  
Kendal Ezell ◽  
Anthony Boyle ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Polymer Foams ◽  
X Ray

scholarly journals Ferromagnetic sand: A possible MRI hazard

2018 ◽  
Vol 31 (6) ◽  
pp. 614-616 ◽  
Author(s):  
Emil Jernstedt Barkovich ◽  
Matthew Jernstedt Barkovich ◽  
Christopher Hess
Keyword(s):  
San Francisco ◽  
Medical Devices ◽  
San Francisco Bay Area ◽  
Resonance Imaging ◽  
Geologic History ◽  
Implantable Medical Devices ◽  
Bay Area ◽  
Geographic Regions ◽  
Imaging Artifact ◽  
Magnetic Resonance Imaging Mri

While the ferromagnetic properties of metallic objects, implantable medical devices, and cosmetics are well known, sand is not generally considered a consequential substance. Beaches in specific geographic regions, including the San Francisco Bay Area, have a propensity for ferromagnetic sand because of their geologic history. We describe a case in which ferromagnetic sand in a patient’s hair coated the magnetic resonance imaging (MRI) scanner bore and caused significant imaging artifact, fortunately with no harm to the patient. We recommend that MRI facilities in areas where ferromagnetic sand is found consider educating technologists and screening patients for recent black sand exposure prior to scanning.

Shape Memory Behavior of Carbon Composites With Functional Interlayer

2018 ◽  
Author(s):  
L. Santo ◽  
L. Iorio ◽  
G. M. Tedde ◽  
F. Quadrini
Keyword(s):  
Carbon Fiber ◽  
Shape Memory ◽  
Polymer Composites ◽  
Polymer Matrix ◽  
Smart Materials ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Carbon Composites ◽  
Three Point Bending ◽  
Functional Behavior

Shape Memory Polymer Composites (SMPCs) are smart materials showing the structural properties of long-fiber polymer-matrix together with the functional behavior of shape memory polymers. In this study, SM carbon fiber reinforced (CFR) composites have been produced by using a SM interlayer between two CFR prepregs. Their SM properties have been evaluated in comparison with traditional structural CFR composites without the SM interlayer by using an especially designed test. Active and frozen forces are measured during a thermo-mechanical cycle in the three-point bending configuration. Experimental results show that SMPCs are able to fix a temporary deformed shape by freezing high stresses.

scholarly journals Shape-Memory Polymeric Artificial Muscles: Mechanisms, Applications and Challenges

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4246 ◽  
Author(s):  
Yujie Chen ◽  
Chi Chen ◽  
Hafeez Ur Rehman ◽  
Xu Zheng ◽  
Hua Li ◽  
...  
Keyword(s):  
Shape Memory ◽  
Smart Materials ◽  
Recent Progress ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Artificial Muscles ◽  
Linkage Design ◽  
Wide Range ◽  
Liquid Crystal Elastomers ◽  
Made In

Shape-memory materials are smart materials that can remember an original shape and return to their unique state from a deformed secondary shape in the presence of an appropriate stimulus. This property allows these materials to be used as shape-memory artificial muscles, which form a subclass of artificial muscles. The shape-memory artificial muscles are fabricated from shape-memory polymers (SMPs) by twist insertion, shape fixation via Tm or Tg, or by liquid crystal elastomers (LCEs). The prepared SMP artificial muscles can be used in a wide range of applications, from biomimetic and soft robotics to actuators, because they can be operated without sophisticated linkage design and can achieve complex final shapes. Recently, significant achievements have been made in fabrication, modelling, and manipulation of SMP-based artificial muscles. This paper presents a review of the recent progress in shape-memory polymer-based artificial muscles. Here we focus on the mechanisms of SMPs, applications of SMPs as artificial muscles, and the challenges they face concerning actuation. While shape-memory behavior has been demonstrated in several stimulated environments, our focus is on thermal-, photo-, and electrical-actuated SMP artificial muscles.

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