Graphene holds promise for thin, ultralightweight, and high‐performance nanoelectromechanical transducers. However, graphene‐only devices are limited in size due to fatigue and fracture of suspended graphene membranes. Here, a lightweight, flexible, transparent, and conductive bilayer composite of polyetherimide and single‐layer graphene is prepared and suspended on the centimeter scale with an unprecedentedly high aspect ratio of 10⁵. The coupling of the two components leads to mutual reinforcement and creates an ultrastrong membrane that supports 30 000 times its own weight. Upon electromechanical actuation, the membrane pushes a massive amount of air and generates high‐quality acoustic sound. The energy efficiency is ≈10–100 times better than state‐of‐the‐art electrodynamic speakers. The bilayer membrane's combined properties of electrical conductivity, mechanical strength, optical transparency, thermal stability, and chemical resistance will promote applications in electronics, mechanics, and optics.

中文翻译：

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相互增强的聚合物-石墨烯双层膜，用于高效节能的声传导

石墨烯有望用于薄，超轻和高性能的纳米机电换能器。但是，由于石墨烯的疲劳和悬浮石墨膜的破裂，仅石墨烯器件的尺寸受到限制。在此，制备了聚醚酰亚胺和单层石墨烯的轻质，柔性，透明且导电的双层复合材料，并以厘米级的比例将其悬浮，前所未有的高长宽比为10 ⁵。这两个组件的耦合导致相互加强，并形成了超强的膜，可支撑自身重量的3万倍。机电驱动时，薄膜会推动大量空气并产生高质量的声音。能源效率是≈比最先进的电动扬声器好10-100倍。双层膜的导电性，机械强度，光学透明性，热稳定性和耐化学性的综合特性将促进在电子，机械和光学方面的应用。