This paper mentions a detail calculation of the equivalent dynamic parameters in differential equations of motion of the electrothermal V-shaped actuator. A heat transfer model for a thin beam (including the dependence of material properties on the temperature) is applied in order to solve more exactly temperature distribution and displacement of V-shaped beam system. Comparing the values of displacement in both calculation and simulation confirmed a higher accuracy of proposed equations. Moreover, a related formula between the minimum conversion stiffness and driving voltage amplitude is analyzed and examined to avoid the buckling phenomenon may occur in V-shaped beam system while working at a high voltage.

This article proposes a formula for calculating the nonlinear displacement of the electrothermal V‐shaped actuator aims to determine more accurately its displacement. The nonlinear displacement model is established based on the axial deformation of V‐beams with two fixed ends. Hence, the theoretical displacements of a particular V‐shaped actuator (i.e. dimension as beam length of 750 μm; beam width of 6 μm; beam thickness of 30 μm; inclined angle of 2°) are compared with the simulation and experimental results. The evaluation shows that our calculation error compared with the simulation and experiment is less than 5% and 12.4%, respectively. This confirmed the advantages of the proposed formula according to the nonlinear displacement model. This work provides a theoretical model for predicting more precisely the displacement of a V‐shaped actuator. The advantage of this model is that it will significantly reduce the time in the design and trial manufacturing process.

This paper presents a thermal transfer model and optimization of a V-beam dimension to improve the critical frequency f_C (i.e., expanding the effective working frequency range) of an electrothermal V-shaped actuator (EVA). The obtained results are based on applying the finite difference model, a method for calculating the critical frequency, as well as conditions to ensure the mechanical stability and thermal safety of EVA. The influence of beam dimensions (i.e., length L, width , and incline angle θ of the beam) on the variation of critical frequency f_C is investigated and evaluated. Moreover, the particle swarm optimization (PSO) algorithm is used to figure out the optimal beam dimensions aiming to increase the critical frequency while satisfying conditions such as mechanical stability, thermal safety, and suitable displacement of EVA. With the optimal dimensions of V-beam (L = 679 µm, = 4 µm, and θ = 1.8°), the critical frequency of the V-shaped actuator can be achieved up to 136.22 Hz at a voltage of 32 V (average increment of f_C is 33.1% with the driving voltage changing from 16 V to 32 V) in comparison with the nonoptimal structure (f_C is only 102.34 Hz at 32 V).

The paper presents a new electrothermal microgripper with a large amplification ratio and a single photo mask. This microgripper is designed with the 40‐μm‐stroke, which is 3.33 times larger than displacement of the driving V‐shaped actuator. It is successfully fabricated by using SOI‐MEMS technology, with an additional platinum sputtering step to reduce equivalent resistance of V‐beams system as well as the power consumption. The experimental displacement has been tested and compared with nonlinear calculations and simulation results. At a driving voltage of 10 V, the microgripper achieved a displacement of 36 μm, compared to the calculated and simulated values of 45.3 and 40.9 µm, respectively.