Mian A, Newaz G, Vendra L, Rahman N, Georgiev D G, Auner G, Witte R, Herfurth H
Department of Mechanical Engineering, Wayne State University, Detroit, Michigan, USA.
J Mater Sci Mater Med. 2005 Mar;16(3):229-37. doi: 10.1007/s10856-005-6684-1.
Bioencapsulation of medical implant devices, and neural implant devices in particular, requires development of reliable hermetic joints between packaging materials that are often dissimilar. Titanium-polyimide is one of the biocompatible material systems, which are of interest to our research groups at Wayne State University and Fraunhofer USA. We have found processing conditions for successful joining of titanium with polyimide using near-infrared diode lasers or fiber lasers along transmission bonding lines with widths ranging from 200 to 300 microm. Laser powers of 2.2 and 3.8 W were used to create these joints. Laser-joined samples were tested in a microtester under tensile loading to determine joint strengths. In addition, finite element analysis (FEA) was conducted to understand the stress distribution within the bond area under tensile loading. The FEA model provides a full-field stress distribution in and around the joint that cause eventual failure. Results from the investigation provide an initial approach to characterize laser-fabricated microjoints between dissimilar materials that can be potentially used in optimization of bio-encapsulation design.
医疗植入设备的生物封装，尤其是神经植入设备，需要在通常不同的包装材料之间开发可靠的密封接头。钛-聚酰亚胺是生物相容性材料体系之一，韦恩州立大学和美国弗劳恩霍夫研究所的研究团队对其很感兴趣。我们已经找到了使用近红外二极管激光器或光纤激光器沿着宽度为200至300微米的传输键合线成功将钛与聚酰亚胺连接的加工条件。使用2.2瓦和3.8瓦的激光功率来形成这些接头。对激光连接的样品在微型测试仪中进行拉伸加载测试以确定接头强度。此外，进行了有限元分析（FEA）以了解拉伸加载下粘结区域内的应力分布。FEA模型提供了接头内部和周围导致最终失效的全场应力分布。研究结果提供了一种初步方法，用于表征不同材料之间的激光制造微接头，这些微接头可潜在地用于生物封装设计的优化。
