Department of Materials Science and Engineering, The Kroto Research Institute, The University of Sheffield, North Campus, Broad Lane, Sheffield S37HQ, UK.
J Mater Sci Mater Med. 2011 Nov;22(11):2573-81. doi: 10.1007/s10856-011-4436-y. Epub 2011 Sep 6.
Oesophageal cancer is the ninth leading cause of malignant cancer death and its prognosis remains poor. Dysphagia which is an inability to swallow is a presenting symptom of oesophageal cancer and is indicative of incurability. The goal of this study was to design and manufacture an Auxetic structure film and to configure this film as an Auxetic stent for the palliative treatment of oesophageal cancer, and for the prevention of dysphagia. Polypropylene was used as a material for its flexibility and non-toxicity. The Auxetic (rotating-square geometry) structure was made by laser cutting the polypropylene film. This flat structure was welded together to form a tubular form (stent), by an adjustable temperature control soldering iron station: following this, an annealing process was also carried out to ease any material stresses. Poisson's ratio was estimated and elastic and plastic deformation of the Auxetic structure was evaluated. The elastic and plastic deformation behaviours of the Auxetic polypropylene film were evaluated by applying repetitive uniaxial tensile loads. Observation of the structure showed that it was initially elastically deformed, thereafter plastic deformation occurred. This research discusses a novel way of fabricating an Auxetic structure (rotating-squares connected together through hinges) on Polypropylene films, by estimating the Poisson's ratio and evaluating the plastic deformation relevant to the expansion behaviour of an Auxetic stent within the oesophageal lumen.
食管癌是第九大常见恶性癌症死亡原因，其预后仍然较差。吞咽困难是食管癌的主要症状，表明疾病已无法治愈。本研究的目的是设计和制造一种仿生结构薄膜，并将其配置为仿生支架，用于食管癌的姑息治疗和预防吞咽困难。由于聚丙烯具有柔韧性和无毒的特性，因此被用作材料。通过激光切割聚丙烯薄膜来制造仿生（旋转正方形几何）结构。通过可调温度控制的电烙铁工作站将这种扁平结构焊接在一起，形成管状形式（支架）：之后，还进行了退火处理以缓解任何材料应力。估计了泊松比，并评估了仿生结构的弹性和塑性变形。通过施加重复的单轴拉伸载荷来评估仿生聚丙烯薄膜的弹性和塑性变形行为。对结构的观察表明，它最初是弹性变形，然后发生塑性变形。本研究讨论了一种在聚丙烯薄膜上制造仿生结构（通过铰链连接在一起的旋转正方形）的新方法，通过估计泊松比并评估与仿生支架在食管腔内膨胀行为相关的塑性变形。
