Nanogenerators have emerged recently as a new technology for harvesting energy from renewable and clean energy sources. Water in nature carries high amounts of kinetic and electrostatic energy; it is ubiquitous and widely accessible in different forms: i.e. as droplets, flows or waves. Either piezoelectric or triboelectric nanogenerators (PENGs, TENGs) have been shown to be effective for harvesting energy from liquids and ocean but the integration of both transduction mechanisms in a single hybrid device allows to exploit several operating conditions and to optimize performances, overcoming the limits of single components. Current piezo-tribo hybrid devices are mostly based on scarcely durable polymers or thick lead-based ceramic materials. Additionally, they are often limited to a specific application or environment due to their architecture and employed materials. In this work, a multifunctional, flexible and conformal hybrid nanogenerator (HNG) has been developed with a sub-100 µm thickness and with a novel combination of biocompatible thin-film piezo-ceramic and soft polymeric materials, for harvesting energy of different water sources, i.e. impacts, raindrops and buoying waves. The PENG component is based on a double-sided metallized AlN thin film, sputtered on polyimide. The TENG component is made of a metallized porous patch made of a mixture of PDMS and platinum-catalyzed silicone (Ecoflex™), encapsulated by a friction film of Parylene C surface-treated with UV/ozone. As a result, the HNG exhibits non-algebraic enhanced performances: the resulting power densities under tapping are ~ 6.5 mW/m² for PENG, 65 mW/m² for TENG, ~ 230 mW/m² for HNG. Multifunctionality is demonstrated by harvesting energy from different water-conveyed sources (i.e. impacts/breakwaters, raindrops, buoying waves). In particular, the device shows optimal and reliable energy harvesting performance under strong impulsive impacts (~ 0.8 W/m²) and raindrops impacts (~ 9 mW/m²). A custom buoyant device, called piezo-JellyFish (pJF), is proposed to exploit the HNGs for harvesting wave energy, based on a connection of three HNGs acting as oral arms: this system yields ~ 3.2 mW/m², with 3 cm-amplitude standing waves. Finally, the HNG exhibits optimal adhesion on the skin and can be also used for monitoring human motions, revealing its multifunctionality also as a wearable conformal sensor.

纳米发电机已作为一种新技术出现，用于从可再生和清洁能源中收集能量。自然界中的水携带大量动能和静电能。它无所不在，并且以不同的形式被广泛使用：即液滴，流或波。压电或摩擦电纳米发电机（PENG，TENG）均已证明可有效地从液体和海洋中收集能量，但是将两种转导机制集成在一个混合设备中，可以利用多种运行条件并优化性能，从而克服了单个组件。当前的压电-摩擦混合设备主要基于几乎不耐用的聚合物或厚铅基陶瓷材料。另外，由于它们的体系结构和使用的材料，它们通常限于特定的应用程序或环境。在这项工作中，已开发出厚度小于100 µm的多功能，柔性和共形的混合纳米发电机（HNG），并具有生物相容性薄膜压电陶瓷和软聚合物材料的新型结合，以收集不同水源的能量即撞击，雨滴和浮波。PENG组件基于溅射在聚酰亚胺上的双面金属化AlN薄膜。TENG组件由金属化的多孔贴片制成，该贴片由PDMS和铂催化的有机硅（Ecoflex™）的混合物制成，并由经UV /臭氧表面处理的聚对二甲苯C摩擦膜封装。结果，HNG表现出非代数增强的性能：在攻丝下产生的功率密度约为6。²为彭，65毫瓦/米²为TENG，〜230毫瓦/米²为HNG。通过从不同的水源（即冲击/防波堤，雨滴，浮波）中收集能量来证明多功能性。特别是，该设备在强烈的脉冲冲击（〜0.8 W / m ²）和雨滴冲击（〜9 mW / m ²）下显示出最佳且可靠的能量收集性能。提出了一种名为“ Piezo-JellyFish（pJF）”的定制浮力装置，以将三个HNG用作口腔手臂，利用HNG来收集波能：该系统的输出功率约为3.2 mW / m ²，具有3厘米振幅的驻波。最终，HNG在皮肤上表现出最佳的附着力，还可以用于监测人体运动，显示出其多功能性，也可作为穿戴式适形传感器使用。