Fabrication of Solidified Ionic Liquid with 3D Microstructures and Its Application to Vibration Energy Harvester

Abstract

In this study, we propose a solidified ionic liquid with a 3D microstructure to increase its surface area for the performance enhancement of a vibration energy harvester (VEH). By soft lithography in MEMS technologies, the use of a mold is proposed to perform the solidification, polarization, and microstructure transfer of the solidified ionic liquid simultaneously. We fabricated six samples with different surface shapes and sizes to compare the power generation performance characteristics of VEHs using a solidified ionic liquid. According to a vibration test, the performance of the VEH with nanometer roughness was improved at a 10 Hz frequency. Also, the output power of the VEH with a micro-folded hollow conical structure was improved at a 50 Hz frequency.

Recent Advanced Applications of Ionic Liquid for Future Iontronics

“…Also, the amount of electricity generated will increase with increasing surface area in contact with the electrode. To increase the surface area in connection with the electrode, microfabrication techniques have been used to create bumps on the surface of the EDLE to increase the amount of electricity generated [67] . The structure of the VEH is another factor determining the power [68] .…”

“…To increase the surface area in connection with the electrode, microfabrication techniques have been used to create bumps on the surface of the EDLE to increase the amount of electricity generated. [67] The structure of the VEH is another factor determining the power. [68] The extreme electric fields using EDLE which is a next generation EDLs gating allowing for the control of novel states of matter.…”

Demonstration of Non‐contact Out‐of‐Plane Vibration Energy Harvesting Using an Electric‐Double‐Layer Electret

“…The movable electrode was manufactured using electrical discharge machining on a 500 μm-thick phosphor bronze (C5191) substrate. The out-of-plane resonant frequency was designed at 105 Hz by a finite-element-method simulation using COMSOL Multiphysics 5.6, which is higher than those of typical contact-mode EDLE-based VEH devices [3,7]. An EDLE film was prepared by polymerization of an ionic liquid, a photoinitiator, polymer, and base material with UV irradiation [8].…”

“…Thus, a VEH device with EDLEs that utilize EDLs as electrets, is expected to have a higher surface charge density and hence a higher output power, compared to conventional electret-based harvesters. In VEH using EDLEs, contact modes, which requires physical contact between EDLEs and moving counter electrodes, are typically used, and the operating frequency ranges have been limited to 1 to several tens of hertz because of the reliability of the physical contacts [3,7]. To expand the use environment of VEH with EDLEs, we have developed a non-contact mode EDLE VEH device using in-plane vibration [8].…”

Piezoelectric Polymer Multilayer Coating Method for Vibration Energy Harvester

“…(5,6) In particular, the vibration energy harvester (VEH) is being actively researched because vibration is ubiquitous in the environment and has relatively high energy density. (7) There are several types of VEH, i.e., electrostatic, (8) electromagnetic, (9) friction, (10) ionic liquid, (11) and piezoelectric, (12) in the micro-electromechanical systems (MEMS) field. The electrostatic type uses the phenomenon that when a charged object approaches a conductor, a charge of the opposite polarity is generated.…”