Charging a supercapacitor-like laminate with ambient moisture: from a humidity sensor to an energy harvester

Abstract

The electromechanically and mechano-electrically active three-layered laminate composed of a Nafion membrane, carbide-derived carbon-based electrodes, and a 1-ethyl-3-methylimidazolium trifluoromethanesulphonate ionic liquid electrolyte responds to humidity gradient and can therefore serve as a differential humidity sensor or an energy harvesting element. The hydrophilic nature of all constituents of the laminate promotes sorption and diffusion of water across the membrane, causing large volumetric effects. Diffusion of water and the formation of a hydration shell around the ionic groups reorient and dislocate the ionic liquid ions, which in turn induce the formation of an electric charge across the electrodes exposed to different levels of ambient humidity. The generated electric charge can be registered as a voltage or electric current between the electrodes. Furthermore, the supercapacitor-like properties of the laminate allow storage of the electric charge in the same laminate, where it was generated.

In situ scanning electron microscopy study of strains of ionic electroactive polymer actuators

“…This IEAP material was fabricated onsite using the direct assembly process, first introduced by Akle et al (2006). Therefore, its mechanical and electrical properties, including the bending strain, are nearly identical to those described by Akle et al Its fabrication was described in detail by Palmre et al (2009) and its electromechanical properties by Vunder et al (2012) and Must et al (2013). In this article, we will refer to it as the CPC.…”

Molecular dynamics simulation of the behaviour of water in nano-confined ionic liquid–water mixtures

“…[2]. The answer to this question is of great importance for engineering of supercapacitors [11], electromechanical actuators [49], motion and electrochemical sensors [50], as well as energy harvesters [51]. In particular, our model can be applied to accelerate the transition from sealed prototypes to in-air-operable devices.…”

“…Wherein, the high water content in these devices has certain advantages, such as decreased viscosity of the electrolyte and, thus, increased response speed as well as bending curvatures. Furthermore, the sensitivity to humidity turns the electromechanical actuators into good mechanical sensors, and the reversible sorption of water can be employed in energy harvesting [51].…”

Ionic electroactive polymer artificial muscles in space applications

“…The IEAP actuators can respond to a low-voltage signal with a large bending stroke without requiring rotating parts, shafts, or precautions against friction. An IEAP actuator can sense motion10 or moisture11, harvest energy12, and store electric energy as a supercapacitor13, and the same portion of the laminate can perform several different functions. The unsophisticated structure of the three-layer laminate allows the applications to be downscaled in a natural way using intersection.…”