CAREER: High Force, High Speed Electro-Thermal Micro-Actuators: Design, Fabrications, and Applications

缺乏合适的致动器限制了硅基微系统的发展。对于平面内驱动，最好的竞争者是静电和热致动器，但前者需要高驱动电压，并且两者都只在大约1-10 uN的范围内提供力。该提案提出了一种新型电热微致动器，承诺将力增加100倍，驱动电压降低10倍。它们利用局部热应力引起的变形，在不影响位移的情况下有效地产生大的力。该装置将采用两种互补的方法进行设计，并通过结合实验优化设计的数值分析进一步完善。提供直线、圆形和定制运动轨迹的设计将被开发和评估性能标准，如输出力和位移、输入功率、驱动电压、响应速度、设备寿命、轨迹误差、机械振动等。此外，还将开发出“尺蠖”等时序发动机，这种发动机可以在备用功率可以忽略的情况下提供大排量和动力。设计将采用多种技术制造，以便对性能和退化机制进行比较评估。提出了无掩模工艺变化的标准技术，以选择性限制热量和电流通量，最大限度地减少功耗和响应时间。初步结果表明，在标准工艺条件下，静位移100微米，峰值力1 mN是可行的。提出了几种应用，在各个性能方面具有互补的需求：扫描探针显微镜定位器；微光机械系统中光学元件定位器以及用于高频通信系统的滑动分流器。从长远来看，这些驱动器还将用于开发触觉界面，例如用于模拟显微手术。一个教育目标是通过早期招募计划和与学生团体的互动，增加MEMS研究社区中代表性不足的群体的参与。另一个是利用实际工程项目促进跨学科教育，迫使多个专业的融合，以填补相关部门之间的教学空白。这些努力将通过与工业界的相互作用得到加强。

The absence of suitable actuators limits the development of silicon-based microsystems. For in-plane actuation, the best contenders are electrostatic and thermal actuators, but the former require high drive voltages, and both deliver forces in the range of only about 1-10 uN. This proposal addresses a new class of electrothermal microactuators that promises 100X increase force and 10X reduction in drive voltage. They leverage deformations caused by localized thermal stresses to efficiently produce large forces without compromising displacement.The devices will be designed by two complementary approaches, and further refined by numerical analysis in conjunction with optimal design of experiments. Designs that offer rectilinear, circular and customized loci of motion will be developed and evaluated for performance criteria such as output force and displacement, input power, drive voltage, response speed, device lifetime, trajectory errors, mechanical vibration, etc. Time-sequenced engines such as inchworms, which offer high displacement and force with negligible standby power, will also be developed. Designs will be fabricated in multiple technologies to permit comparative evaluations of performance and degradation mechanisms. Maskless process variations are proposed for standard technologies for selective confinement of heat and current flux, which minimize power consumption and response time.Preliminary results indicate that static displacements 100 microns and peak forces 1 mN are feasible with standard technologies. Several applications are proposed, with complementary demands on various performance aspects: a positioner for scanning probe microscopy; a positioner for optical elements in a micro-optomechanical system; and a sliding shunt for high-frequency telecommunication systems. In the long term these actuators will also be used to develop haptic interfaces, e.g. for simulating microsurgery.One educational objective is to increase the participation of under-represented groups in the MEMS research community using early recruitment programs and interaction with student groups. Another is to facilitate interdisciplinary education using practical engineering projects that force the convergence of multiple specialties to fill the pedagogical gaps between relevant departments. These efforts will be reinforced by interactions with industry.