Development of high temperature electrodeposited LIGA MEMS materials

来自Forschungszentrum Karlsruhe（FZK，德国）和约翰霍普金斯大学（JHU，美国）的一个国际多学科研究小组将开展一项合作计划，开发用于高温MEMS应用的新型电沉积LIGA材料。技术动机来自于扩展当前MEMS材料的可靠性和功能性的需要。目前的LIGA处理通常导致电沉积的镍结构具有高的纵横比和有吸引力的室温性能平衡，但热暴露已被证明会导致微结构不稳定性和显著的性能退化，这目前限制了LIGA结构在高温MEMS应用中的使用，例如作为模具、热交换器、热致动器和发电装置。计划努力开发共沉积合金、弥散强化复合材料和高温镍基高温合金。将对加工参数进行明智的控制和优化，并将其与所得的微观结构和伴随的机械性能相关联。FZK将解决与微米级结构制造相关的加工问题，JHU最近开发的新型高温微样品测试技术将用于测量这些新材料的全方位机械性能。两个机构之间的密切合作将需要履行该提案的科学使命，研究生和高级研究员科学家的综合交流将为这种合作创造工具，并为学生提供独特的教育体验。

An international multidisciplinary research team from Forschungszentrum Karlsruhe (FZK, Germany) and John Hopkins University (JHU, USA) will undertake a collaborative programm to develop novel electrodeposited LIGA materials for high temperature MEMS applications. The technological motivation is derived from a need to expand the reliability and funcionality of current MEMS materials. Current LIGA processing generally results in electrodeposited nickel structures with high aspect ratios and an attractive balance of room temperature properties, but thermal exposure has been shown to result in microstructural instabilities and significant property degradation, which currently limit the use of LIGA structures in elevated temperature MEMS applications, e.g. as molds, heat exchangers, thermal actuators, and power generation devices. Efforts to develop co-deposited alloys, dispersion strengthened composites and high temperature Ni-base superalloys are planned. Judicious control and optimisation of processing parameters will be performed and related to the resultant microstructure and attendant mechanical properties. Processing issues related to the fabrication of micron-sized structures will be addressed at FZK, and novel elevated temperature microsample testing techniques, recently developed at JHU, will be employed to measure the full-range of mechanical properties of these new materials. Close collaboration between the two institutions will be required to fulfill the scientific mission of the proposal, and integrated exchanges of graduate students and senior researcher scientists will create the vehicle for this collaboration and provide a unique educational experience for the students.