Electricity modulation of a water motion active transducer via surface functionality control

Abstract Recently, the water motion active transducer, an electricity generator which uses water contact variations, has attracted much attention as an eco-friendly energy harvesting device. In order to understand the electricity generation induced by ionic behavior in water at the solid-liquid interface of a water motion active transducer accurately and apply it to a wide range of applications, fundamental study of the surface functionalities at the solid-liquid interface of the water motion active transducer is essential. However, most studies in the field of water motion active transducer still remain them for a high power performance. Herein, through an investigation of surface functionality control at a solid-liquid interface, we modulate the generating electricity of a water motion active transducer and successfully demonstrate its potential toward the realization of a novel self-powered pH sensor. For both hydrophobicity and surface functionality control at the solid-liquid interface, we used a self-assembled monolayer technique with APTES ((3-aminopropyl) triethoxysilane) and POTS (1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane). Through control of the surface functionalities at the interface, we show substantial potential for the modulation of the generating electricity. In addition, the unique electric characteristics of this device offer a fundamental understanding of the origin of electricity generation at solid-liquid interfaces induced by water motion and provide a more accurate understanding of the ionic behaviors occurring at solid-liquid interfaces toward the novel ion-functional devices.