A guide to shape memory and superelasticity in Nitinol medical devices

2004 ◽  
Vol 13 (4) ◽  
pp. 218-221 ◽  
Author(s):  
A.R. Pelton ◽  
T.W. Duerig ◽  
D. Stöckel
Keyword(s):  
Author(s):  
Muhammad Y. Razzaq ◽  
Markus Reinthaler ◽  
Mark Schröder ◽  
Christian Wischke ◽  
Andreas Lendlein

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4660
Author(s):  
Grace K. Fletcher ◽  
Landon D. Nash ◽  
Lance M. Graul ◽  
Lindy K. Jang ◽  
Scott M. Herting ◽  
...  

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.


MRS Advances ◽  
2017 ◽  
Vol 2 (47) ◽  
pp. 2529-2536
Author(s):  
Magdalena Mazurek-Budzyńska ◽  
Muhammad Y. Razzaq ◽  
Gabriel Rokicki ◽  
Marc Behl ◽  
Andreas Lendlein

ABSTRACTThe simultaneous capability of high-strain deformation and high shape recovery ratio constitutes a great challenge in design of the shape-memory polymers. Here we report on poly(carbonate-urea-urethane)s (PCUUs) synthesized by a precursor route, based on oligo(alkylene carbonate) diols, L-lysine diisocyanate (LDI), and water vapor. When programed with a strain of εprog = 800%, the PCUU networks exhibited a one-way shape-memory effect (1W-SME) with excellent shape fixity (> 97%) and shape recovery (> 99%) ratios. The switching temperatures (Tsw) varied between 50 and 56 °C and correlated to the melting transitions of the switching domains. The obtained PCUUs capable of high-strain are interesting candidate materials for degradable biomaterials as required in smart medical devices.


2009 ◽  
Vol 30 (7) ◽  
pp. 2431-2434 ◽  
Author(s):  
V. Lorenzo ◽  
A. Díaz-Lantada ◽  
P. Lafont ◽  
H. Lorenzo-Yustos ◽  
C. Fonseca ◽  
...  

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