Thermal Actuator for Micro Stress Tensor Test

In this work, a V shape thermal actuator, capable of generating force and displacement on a central shuttle, was built on a SOI wafer with 5 μm thick-device layer. This device uses Joule heating effect to expand 10 pair of bent beams causing the movement of the central shuttle. This kind of thermal actuator is known as V shape thermal actuator and it has already been studied on literature [1]. The device has a 6 pair of sink beams to control the heat flux on the central shuttle. The displacement can be measured by the assessment of the change in capacitance of 35 pair of parallel-plate capacitors connected to the shuttle. Finite Element Method (FEM) simulations were performed and the experimental temperature and displacement behaviors were compared to the simulation results. An experimental displacement of 0.5 土 0.06 μm was measured while applying 8 V in the thermal actuator. For the same applied voltage, the simulation results present a displacement of 0.42 μm, which is in good agreement with the experimental results. The temperature distribution behaves like the FEM simulation where the experimental value is 250 ºC and the simulation value is about 220 ºC. Experimentally the device shows out-of-plane displacement, which will be further characterized. Also, calibration of capacitance change with displacement will be performed. In the future, the aim is to place a copper thin film in the middle of the central shuttle to perform traction tests in-situ TEM.