title: Waving potential in graphene.
abstract: Nanoscale materials offer much promise in the pursuit of high-efficient energy conversion technology owing to their exceptional sensitivity to external stimulus. In particular, experiments have demonstrated that flowing water over carbon nanotubes can generate electric voltages. However, the reported flow-induced voltages are in wide discrepancy and the proposed mechanisms remain conflictive. Here we find that moving a liquid-gas boundary along a piece of graphene can induce a waving potential of up to 0.1 V. The potential is proportional to the moving velocity and the graphene length inserted into ionic solutions, but sharply decreases with increasing graphene layers and vanishes in other materials. This waving potential arises from charge transfer in graphene driven by a moving boundary of an electric double layer between graphene and ionic solutions. The results reveal a unique electrokinetic phenomenon and open prospects for functional sensors, such as tsunami monitors.
authors.affiliation: 1] State Key Laboratory of Mechanics and Control of Mechanical Structures, The Key Laboratory of Intelligent Nano Materials and Devices of DoE, Institute of Nano Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China [2].
authors.forename: Jun
authors.initials: J
authors.lastname: Yin
authors.affiliation: 1] State Key Laboratory of Mechanics and Control of Mechanical Structures, The Key Laboratory of Intelligent Nano Materials and Devices of DoE, Institute of Nano Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China [2].
authors.forename: Zhuhua
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Mechanics and Control of Mechanical Structures, The Key Laboratory of Intelligent Nano Materials and Devices of DoE, Institute of Nano Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
authors.forename: Xuemei
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Mechanics and Control of Mechanical Structures, The Key Laboratory of Intelligent Nano Materials and Devices of DoE, Institute of Nano Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Mechanics and Control of Mechanical Structures, The Key Laboratory of Intelligent Nano Materials and Devices of DoE, Institute of Nano Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
authors.forename: Jianxin
authors.initials: J
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Mechanics and Control of Mechanical Structures, The Key Laboratory of Intelligent Nano Materials and Devices of DoE, Institute of Nano Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
authors.forename: Yaqing
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Mechanics and Control of Mechanical Structures, The Key Laboratory of Intelligent Nano Materials and Devices of DoE, Institute of Nano Science, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
authors.forename: Wanlin
authors.initials: W
authors.lastname: Guo