Design and finite element analysis of electromechanical tapered nano-tweezers for extending the tweezering range

Extending the tweezering range of the electromechanical nano-tweezers is of high interest. Herein, a pair of nano-tweezers with linearly varying width is designed to achieve higher tweezering rage. To this end, using the modified couple stress theory and considering the surface elasticity, the nonlinear equation of motion of tapered nano-tweezers is developed. The electrical field is simulated by incorporating the fringing field effect. Also, the impact of Casimir force is considered in the developed model. A finite element procedure is established based on Euler–Bernoulli beam theory to investigate the nano-tweezers' pull-in behavior. The role of influential parameters, including the size dependency, the surface effect, Casimir force, and the width ratio on the tweezering range and instability voltage, are investigated. The outcomes demonstrate that the nano-tweezers with the converging geometry exhibit a higher tweezering range. Notably, the nano-tweezers with the needle configuration can extend the tweezering range up to 53% of the initial gap. (author)