Shape memory alloy (SMA) actuators can provide significant advantages for small-scale robotics given their robustness, energy density, and low voltage actuation. However, NiTi thin films typically found in SMA microactuators do not often provide useful forces and displacements for microrobotic applications. This work presents a fabrication process in which NiTi thin film actuators are integrated with two-photon polymerization (TPP) 3D printing to scale these actuators up for use in mesoscale systems. Individual unimorph actuators are characterized with respect to uniformity across many actuators so that actuators can be arrayed together for even larger forces or combined toward the operation of complex mechanisms. The resulting actuators are fast to prototype, reliable and stable (up to 5000 cycles), and can utilize complex geometries that are otherwise challenging to achieve with conventional MEMS microfabrication techniques. A 2D positioner is demonstrated by combining six individually controlled actuators with conventional mm-scale fabrication techniques (3D stereolithography printing, wire bonding and PCB assembly). The actuators are controlled by a commercial microcontroller and powered using a standard Lithium polymer battery. [2020-0208]

中文翻译：

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使用微机器人增材制造的薄膜 NiTi 致动器的分层集成

鉴于其坚固性、能量密度和低电压驱动，形状记忆合金 (SMA) 执行器可为小型机器人提供显着优势。然而，通常在 SMA 微致动器中发现的 NiTi 薄膜通常不会为微机器人应用提供有用的力和位移。这项工作提出了一种制造过程，其中 NiTi 薄膜致动器与双光子聚合 (TPP) 3D 打印相结合，以扩大这些致动器以用于中尺度系统。单个 unimorph 致动器的特征在于跨多个致动器的均匀性，因此致动器可以排列在一起以获得更大的力或组合以实现复杂机构的操作。由此产生的执行器可快速制作原型，可靠且稳定（高达 5000 次循环），并且可以利用传统的 MEMS 微制造技术难以实现的复杂几何形状。通过将六个独立控制的致动器与传统的毫米级制造技术（3D 立体光刻印刷、引线键合和 PCB 组装）相结合，展示了 2D 定位器。执行器由商用微控制器控制，并使用标准锂聚合物电池供电。[2020-0208]