To examine the impact of the strain rate on the anisotropic mechanical characteristics of single-crystal silicon, nanoindentation and micro-tensile–compression tests were performed. This study analyzed the effects of varying crystal orientations at different strain rates on load–displacement behavior, elastic modulus, hardness, fracture toughness, and true stress–strain responses. The nanoindentation results showed that at room temperature, single-crystal silicon exhibited an elastic recovery rate of approximately 42%. Notably, the elastic modulus remained unaffected by strain rate variations, whereas hardness increased with higher strain rates. Fracture toughness at room temperature displayed marked anisotropy, with the orientation exhibiting the lowest value at 0.691 MPa·m^1/2 and the orientation showing the highest one at 0.797 MPa·m^1/2. Additionally, tensile and compression experiments revealed that the fracture strength of -oriented silicon increased from 117 MPa at a strain rate of 0.001 s⁻¹ to 550 MPa at a strain rate of 0.01 s⁻¹.

The electrothermal actuator designed in this article is used to play a delayed release role in the security mechanism of MEMS security systems, which requires periodic control signals to drive the centrifugal slider and other components of the security device through electric thermal force multi physics coupling in a complex mechanical working environment, enabling them to unlock and achieve reliable release of the security function. This article adopts the lumped parameter design method to establish a mathematical model of the electrothermal micro-actuator, and conducts theoretical analysis. Through finite element analysis and calculation, an electric thermal force coupling model of the micro actuator is established, and electrothermal energy conversion effect and the effects of V-beam parameters on the deformation and displacement of electrothermal micro-actuator are studied.