Bernal Rodrigo A, Ramachandramoorthy Rajaprakash, Espinosa Horacio D
Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, USA.
Department of Mechanical Engineering, Northwestern University, Evanston, IL 60208, USA; Department of Theoretical and Applied Mechanics, Northwestern University, Evanston, IL 60208, USA.
Ultramicroscopy. 2015 Sep;156:23-8. doi: 10.1016/j.ultramic.2015.04.017. Epub 2015 Apr 28.
MEMS and other lab-on-a-chip systems are emerging as attractive alternatives to carry out experiments in situ the electron microscope. However, several electrical connections are usually required for operating these setups. Such connectivity is challenging inside the limited space of the TEM side-entry holder. Here, we design, implement and demonstrate a double-tilt TEM holder with capabilities for up to 9 electrical connections, operating in a high-resolution TEM. We describe the operating principle of the tilting and connection mechanisms and the physical implementation of the holder. To demonstrate the holder capabilities, we calibrate the tilting action, which has limits of ±15°, and establish the insulation resistance of the electronics to be 36GΩ, appropriate for measurements of currents down to the nano-amp (nA) regime. Furthermore, we demonstrate tensile testing of silver nanowires using a previously developed MEMS device for mechanical testing, using the implemented holder as the platform for electronic operation and sensing. The implemented holder can potentially have broad application to other areas where MEMS or electrically-actuated setups are used to carry out in situ TEM experiments.
微机电系统(MEMS)和其他芯片实验室系统正成为在电子显微镜中原位进行实验的有吸引力的替代方案。然而,操作这些装置通常需要几个电气连接。在透射电子显微镜(TEM)侧入式样品架的有限空间内实现这种连接具有挑战性。在此,我们设计、实现并展示了一种双倾TEM样品架,它能够在高分辨率TEM中实现多达9个电气连接。我们描述了倾斜和连接机构的工作原理以及样品架的物理实现方式。为了展示样品架的能力,我们校准了倾斜动作(其极限为±15°),并确定电子器件的绝缘电阻为36GΩ,适用于测量低至纳安(nA)量级的电流。此外,我们使用先前开发的用于机械测试的MEMS器件,以所实现的样品架作为电子操作和传感平台,展示了银纳米线的拉伸测试。所实现的样品架可能在其他使用MEMS或电动装置进行原位TEM实验的领域有广泛应用。