Microneedles(MNs)is an emerging technology that employs needles ranging from 10 to 1000μm in height,as a minimally invasive technique for various procedures such as therapeutics,disease monitoring and diagnostics.The...Microneedles(MNs)is an emerging technology that employs needles ranging from 10 to 1000μm in height,as a minimally invasive technique for various procedures such as therapeutics,disease monitoring and diagnostics.The commonly used method of fabrication,micromolding,has the advantage of scalability,however,micromolding is unable to achieve rapid customizability in dimensions,geometries and architectures,which are the pivotal factors determining the functionality and efficacy of the MNs.3D printing offers a promising alternative by enabling MN fabrication with high dimensional accuracy required for precise applications,leading to improved performance.Furthermore,enabled by its customizability and one-step process,there is propitious potential for growth for 3D-printed MNs especially in the field of personalized and on-demand medical devices.This review provides an overview of considerations for the key parameters in designing MNs,an introduction on the various 3D-printing techniques for fabricating this new generation of MNs,as well as highlighting the advancements in biomedical applications facilitated by 3D-printed MNs.Lastly,we offer some insights into the future prospects of 3D-printed MNs,specifically its progress towards translation and entry into market.展开更多
传统的岩石取样方法以及模具浇筑常受到人工操作误差及取样内部结构复杂差异大的影响,导致岩石试件获取的周期时间长,精度低,造成试样的力学试验结果离散性大。3D打印技术具有精度高、周期短、打印材料多样化等优点,考虑到岩石力学研究...传统的岩石取样方法以及模具浇筑常受到人工操作误差及取样内部结构复杂差异大的影响,导致岩石试件获取的周期时间长,精度低,造成试样的力学试验结果离散性大。3D打印技术具有精度高、周期短、打印材料多样化等优点,考虑到岩石力学研究受到试件各向异性、结构面复杂、随机性高及试件制备存在误差等因素影响,为寻求能够模拟天然煤岩的3D打印材料,选取了聚乳酸塑料(PLA)、光敏树脂材料SLA600及Vero White Plus,以及覆膜砂粉末材料4种材料制备标准力学试验试件进行单轴压缩试验,获取了4种材料的3D打印试样的力学参数及应力-应变曲线,并对比分析了它们与煤岩的表观破裂模式的相似性。结果表明:光敏树脂材料Vero White Plus与砂岩岩样的峰值强度、杨氏模量、泊松比及应力-应变曲线整体趋势相近;覆膜砂材料与所选煤样的峰值强度、杨氏模量及应力-应变曲线相近;表观破坏模式方面,PLA材料未发生与煤岩相似的脆性破坏;两种光敏树脂材料均发生了拉张与剪切破裂,其中SLA600材料表现出局部膨胀性,Vero White Plus材料与SLA600相比更适合模拟高强度的脆性硬岩;而覆膜砂3D打印试件的破裂特征及力学特性与低强度软岩相似,可作为低强度的脆性煤体的3D打印相似材料。展开更多
基金supported by the National Additive Manufacturing Innovative Cluster(NAMIC)POC Funding,Agency for Science,Technology and Research(A*STAR)Career Development Fund and BMRC Central Research Fund(CRF,ATR)NHG Medical Technologies&Innovations(CMTi)and National Health Innovation Centre Singapore(NHIC)Joint MedTech Grant.
文摘Microneedles(MNs)is an emerging technology that employs needles ranging from 10 to 1000μm in height,as a minimally invasive technique for various procedures such as therapeutics,disease monitoring and diagnostics.The commonly used method of fabrication,micromolding,has the advantage of scalability,however,micromolding is unable to achieve rapid customizability in dimensions,geometries and architectures,which are the pivotal factors determining the functionality and efficacy of the MNs.3D printing offers a promising alternative by enabling MN fabrication with high dimensional accuracy required for precise applications,leading to improved performance.Furthermore,enabled by its customizability and one-step process,there is propitious potential for growth for 3D-printed MNs especially in the field of personalized and on-demand medical devices.This review provides an overview of considerations for the key parameters in designing MNs,an introduction on the various 3D-printing techniques for fabricating this new generation of MNs,as well as highlighting the advancements in biomedical applications facilitated by 3D-printed MNs.Lastly,we offer some insights into the future prospects of 3D-printed MNs,specifically its progress towards translation and entry into market.
文摘传统的岩石取样方法以及模具浇筑常受到人工操作误差及取样内部结构复杂差异大的影响,导致岩石试件获取的周期时间长,精度低,造成试样的力学试验结果离散性大。3D打印技术具有精度高、周期短、打印材料多样化等优点,考虑到岩石力学研究受到试件各向异性、结构面复杂、随机性高及试件制备存在误差等因素影响,为寻求能够模拟天然煤岩的3D打印材料,选取了聚乳酸塑料(PLA)、光敏树脂材料SLA600及Vero White Plus,以及覆膜砂粉末材料4种材料制备标准力学试验试件进行单轴压缩试验,获取了4种材料的3D打印试样的力学参数及应力-应变曲线,并对比分析了它们与煤岩的表观破裂模式的相似性。结果表明:光敏树脂材料Vero White Plus与砂岩岩样的峰值强度、杨氏模量、泊松比及应力-应变曲线整体趋势相近;覆膜砂材料与所选煤样的峰值强度、杨氏模量及应力-应变曲线相近;表观破坏模式方面,PLA材料未发生与煤岩相似的脆性破坏;两种光敏树脂材料均发生了拉张与剪切破裂,其中SLA600材料表现出局部膨胀性,Vero White Plus材料与SLA600相比更适合模拟高强度的脆性硬岩;而覆膜砂3D打印试件的破裂特征及力学特性与低强度软岩相似,可作为低强度的脆性煤体的3D打印相似材料。
