薄膜反射镜的单电极控制静电成形

Control of membrane mirror shape by single electrode

考虑薄膜反射镜具有质量轻、柔韧性好、可折叠等优点,研究了由静电拉伸法制备薄膜反射镜的新技术。介绍了薄膜反射镜的静电成形机理,计算了单电极模式下薄膜所受力场,设计了单电极式薄膜反射镜的控制实验。给出了控制成型所需的主要参数,设计了薄膜反射镜的夹持结构和控制电路,并利用刀口仪测量了形成的反射面的焦距。实验结果显示,未通电时薄膜反射镜面形的PV值达到11.14λ,RMS值为1.86λ,在10000V的高压下可以形成焦距约为2.1m的反射镜面。通过Zernike拟合验证了数据的可靠性,结果表明,通过改善夹持结构精度和选取性能优良的薄膜材料,反射镜面形精度可进一步提高。

Electrostatic stretching is a new technique developed in recent years for fabricating membrane mirrors with light, good flexible and collapsible properties. Based on the electrostatic shaping principle of a membrane mirror, the force field of the stretched membrane was calculated by a single electrode mode, and the support structure of the membrane and its control circuit were designed. Then, several kind of technological parameters for controlling membrane shape were given and the focus of reflective surface of the membrane was measured by a knife-edge. The experimental results show that the PV and RMS values of the membrane mirror are 11.14λ and 1.86λ, without applying an electric force respectively, and the focus of reflective surface of the membrane is about 2.1 m with a 10 000 V high voltage. Finally, the Zernike fitting was used to verify the reliability of the data, and it suggests that the surface accuracy can be improved further by optimizing the holding structure and selecting excellent membrane materials.