Multi-Degree-of-Freedom Electrothermal Microgripper Based on Al-Polyimide Bimorph Structures

Efficient and precise manipulation of micro-targets is essential for advancing micro-assembly applications. This paper presents an electrothermal microgripper integrated with a multi-degree-of-freedom platform, enabling over$600 \mu \mathrm{m}$of vertical displacement and approximately 10° of out-of-plane deflection. These capabilities significantly enhance manipulation efficiency compared to traditional systems that rely on external platforms. The actuator features an Al-Photosensitive Polyimide (PSPI) bimorph structure, which improves both deformation capability and robustness. Experimental results demonstrate that the microgripper can efficiently manipulate a chip capacitor (with a size of$1 \times 0.5 \times 0.2 \text{mm}^{3}$, a mass of about 0.6 mg). These characteristics underscore its strong potential for micro-assembly, providing a novel solution for handling diverse micro-targets in complex assembly tasks.