Heung Soo Kim

Piezoelectric thin films offer a number of advantages in various applications, such as high energy density harvesters, a wide dynamic range, and high sensitivity sensors, as well as large displacement and low power consumption actuators. This review covers the available material forms and applications of piezoelectric thin films: lead zirconate titanate (PZT)-based thin films, lead-free piezoelectric thin films, piezopolymer films, cellulose-based electroactive paper (EAPap), and many other thin

Structural health monitoring (SHM) methods are essential to guarantee the safety and integrity of composite structures, which are extensively utilized in aerospace, automobile, marine, and infrastructure industry. The deterioration of composite structures is primarily caused by operational and environmental variability. To address this issue, artificial intelligence (AI) techniques are being integrated into the SHM systems to enhance the performance of composite structures via digital transforma

Abstract Recently, prognostic and health management (PHM) has become a prominent field in modern industry. The rotate vector (RV) reducer is one of the widely used mechanical components in industrial systems, specifically in robots. The RV reducer is known for its unique characteristics of small size, efficient speed transmission, and high torsion. The RV reducer is prone to several kinds of faults, due to its continuous operation in an industrial robot. To keep the operation smooth and steady,

A procedure has been developed to investigate the dynamic response of composite structures, with embedded multiple delaminations. A recently developed improved layerwise composite laminate theory is extended to model composite laminates of moderately large thickness with delamination. The theory accurately predicts interlaminar shear stresses while maintaining computational efficiency. Natural frequencies and mode shapes are computed for cross-ply laminates with delaminations placed at different

The highly efficient hydrothermal chemical reaction was used to synthesis the manganese [email protected] doped graphene oxide/polypyrrole (MnO2@NGO/PPy) composites as a high capacitance electrode material for supercapacitors. The prepared composites structural and surface properties were confirmed by spectral and electron microscopic studies, respectively. The electrochemical cyclic voltammetric analysis carried out for MnO2@NGO and MnO2@NGO/PPy electrodes using potassium hydroxide electrolyte.

We report on the recent progress and development of research into cellulose-based electro-active paper for bending actuators, bioelectronics devices, and electromechanical transducers. The cellulose electro-active paper is characterized in terms of its biodegradability, chirality, ample chemically modifying capacity, light weight, actuation capability, and ability to form hybrid nanocomposites. The mechanical, electrical, and chemical characterizations of the cellulose-based electro-active paper

As a compact and durable design concept, piezoelectric energy harvesting skin (PEH skin) has been recently proposed for self-powered electronic device applications. This study aims to develop an electromechanically-coupled analytical model of PEH skin considering the inertia and stiffness effects of a piezoelectric patch. Based on Kirchhoff plate theory, Hamilton's principle is used to derive the electromechanically-coupled differential equation of motion. Due to the geometric discontinuity of t