Rollable, Stretchable, and Reconfigurable Graphene Hygroelectric Generators

Adv Mater. 2019 Jan;31(2):e1805705. doi: 10.1002/adma.201805705. Epub 2018 Nov 15.

Abstract

Moisture-triggered electricity generation has attracted much attention because of the effective utilization of the water-molecule diffusion process widely existing in atmosphere. However, the monotonous and rigid structures of previously developed generators have heavily restricted their applications in complex and highly deformable working conditions. Herein, by a rational configuration design with a versatile laser processing strategy, graphene-based hygroelectric generators (GHEGs) of sophisticated architectures with diversified functions such as rollable, stretchable, and even multidimensional transformation are achieved for the first time. More importantly, a wide range of 3D deformable generators that can automatically assemble and transform from planar geometries into spacial architectures are also successfully fabricated, including cubic boxes, pyramids, Miura-ori, and footballs. These GHEGs demonstrate excellent electricity-generation performance in curling and elongating states. The generated voltages are easily up to 1.5 V under humidity variation in atmosphere, powering a variety of commercial electronic components. These deformable GHEGs can be applied on complicated surfaces, human bodies, and many more beyond those demonstrated in this work.

Keywords: deformable; direct laser writing; flexible electronics; graphene; hygroelectric generators.