Design optimization of an electrothermal MEMS microgripper with integrated sensing for enhanced gripping stroke performance

Abstract A high gripping stroke for microelectromechanical systems (MEMS) microgrippers enables a reliable manipulation of objects and enhances their applicability. This work presents the design and optimization of an electrothermally actuated MEMS microgripper for enhanced gripping stroke performance. The design incorporates a two-stage displacement amplification mechanism and integrated electrothermal sensing for gripping force and displacement measurement. A multi-objective genetic algorithm is employed to systematically optimize the structural parameters achieving a large gripping stroke for a low power input. Finite element simulations are performed, and the results predict that the optimized design achieves a larger gripping stroke of 98.86 μ m for a low operating voltage of 15 V thereby optimizing the power consumption to 168.60 mW. The gripping displacement is effectively enhanced by two-stage displacement amplification without compromising structural and thermal stability of the proposed MEMS microgripper. The finite element method simulations indicate that the application of multi-objective optimization enhances the gripping stroke by 12.01%. The integrated electrothermal sensor is capable of providing real-time feedback of displacement and gripping force. An analytical model for accurate estimation of the gripping force is developed which confirms a gripping force of 4.67 μ N for maximum actuation voltage. The proposed microgripper demonstrates the combined advantages of low-power consumption, large gripping performance, and integrated sensing, making it highly suitable for tasks involving precision manipulation in biomedical and microsystem applications.