Attaining the information of the hydrodynamic flow rate and direction is essential to the maneuvering of autonomous underwater vehicles (AUVs). This work presents a pillar-based flow sensor that measures hydrodynamic flow rate and direction. We propose a design that mimic the working principle of the neuromast, a ubiquitous organ in fishes that sense the water flow. By utilizing advances in piezo-resistive

The multiple forms of vibration exist in an ambient environment diffusely and already become a considerable object for energy harvesting. However, how to effectively extract low-level, low-frequency, and multi-directional vibration from the ambient environment is becoming a key issue in the field of energy harvesting. To solve this issue, a tower-shaped piezoelectric vibration energy harvester (TS-PVEH)

Wearable sensors are attracting great attentions due to their potential applications in human health monitoring and caring systems. The wide utilization of wearable electronics may cause great burden to the environment, due to the vast contaminants generated in their fabrication and after their usage. Consequently, great efforts are devoted to the eco-friendly strategies for the material and fabrication

Due to an unfortunate oversight the acknowledgment section has been omitted. It should be read: The present research was supported by the research fund of Dankook university in 2021

Increasingly, copper nanopowders are commonly used in conductive inks due to their cost-efficiency compared to silver or gold and excellent electrical conductivity. One of the challenges associated with copper inks is oxidation and to address, we have developed a hybrid copper-based ink by removing the oxide layer of copper powders and coat the powders with a silver shell to protect from oxidation

The hydraulic power take-off (HPTO) is considered as the most promising method to convert wave power to electrical power. This paper presents an experimental assessment of the power conversion of a wave energy converter using HPTO. Based on the experimental results, a modification of accumulator pre-charged pressure and a control strategy were proposed to improve the system performance. System design

Fuel cell hybrid electric construction equipment (FCHECE) is known as a promising solution to achieve the goal of energy saving and environment protection. Energy management strategy is a key technology of FCHECE, which splits the energy flow between power sources. This paper presents a novel optimal energy management strategy for a hybrid electric-powered hydraulic excavator system to enhance power

Motors, which are one of the most widely used machines in the manufacturing field, take charge of a key role in precision machining. Therefore, it is important to accurately estimate the health state of the motor that affects the quality of the product. The research outlined in this paper aims to improve motor fault severity estimation by suggesting a novel deep learning method, specifically, feature

A parametric investigation of a novel ammonia water mixture power generation system is performed in this study. The overall performance and feasibility of the system of the proposed system are assessed from thermoeconomic, conventional exergy and advanced exergy perspectives. For better heat recovery in the existing medium-temperature heat recovery Kalina system, auxiliary solar heater is considered

The use of microreactors in the continuous fluidic system has been rapidly expanded over the past three decades. Developments in materials science and engineering have accelerated the advancement of the microreactor technology, enabling it to play a critical role in chemical, biological, and energy applications. The emerging paradigm of digital additive manufacturing broadens the range of the material

This paper presents a developed manipulator and control method for automatic lapping process applied to a large work surface. A lapping machine consists of a newly designed parallelogram-type 5-axis manipulator and a conventional 3-axis gantry machine. The gantry machine is utilized to precision positioning over a large work area, and the manipulator is controlled by a separate controller for lapping

This paper presents the recent control technologies being researched for floating offshore wind energy system (FOWES). FOWES has been getting many attentions recently as an alternative energy system utilizing vast sustainable wind resource away from land with little restriction by human societies, artificial and natural obstacles. However, not only due to the harsh environmental conditions such as

Selective thin-film removal is needed in many microfabrication processes such as 3-D patterning of optoelectronic devices and localized repairing of integrated circuits. Various wet or dry etching methods are available, but laser machining is a tool of green manufacturing as it can remove thin films by ablation without use of toxic chemicals. However, laser ablation causes thermal damage on neighboring

Under the threat of serious environmental pollution and resource waste, sustainable development and green manufacturing have gradually become a new development trend. A new environmentally sustainable approach, namely, cryogenic air nanofluid minimum quantity lubrication (CNMQL), is proposed considering the unfavorable lubricating characteristic of cryogenic air (CA) and the deficient cooling performance

In this study, a facile and scalable fabrication process of the flexible and transparent tactile sensor array where its operation is based on the triboelectric effect is proposed. The overall process is assisted by the solution based screen printing method, which is well-known as advantageous in the batch fabrication of the electronic devices. The introduction of the batch fabrication process to the

Bulk metallic glasses (amorphous alloys) exhibiting both high hardness and extraordinary thermoplastic forming ability, are perfect mold material for 3D optical microlens array. However, conventional 3D micro fabrication for metallic glass requires Si templates which are extremely costly and eco-unfriendly to machine and demold. In this study, we report a green and low-cost self-aligned multi-ball

Control of thermal conditions in the grinding zone is possible through effective delivery of substances with cooling, lubricating and antiadhesive properties during the machining process. In addition to the benefits of coolants, however, a number of economic and ecological problems arise, which include the costs of purchase, use and maintenance as well as the environmental impact of its disposal. These

Piezoelectric vibration energy harvesting has attracted considerable attention because of its prospects in self-powered electronic applications. There are a many low-velocity waters in nature, such as rivers, seas and oceans, which contain abundant hydrokinetic energy. In this paper, an optimal geometric piezoelectric beam combining magnetic excitation is identified and applied to a vortex-induced

Reliability is the key performance indicator for remanufactured machine tools to be approved by customers. Reliability allocation is an important task that needs to be done in the design phase of remanufactured machine tools to ensure that remanufactured products meet the reliability target requirements. A reliability allocation method for remanufactured machine tools is proposed based on fuzzy evaluation

Salter’s Duck can convert wave energy to mechanical energy with high efficiency up to 90%. The limitations and challenges in the usage of Salter’s Duck for energy production include preventing hydraulic system from the risk of leaking hydraulic oil and removing complex huge fixed bracket. This paper presents the conceptual design and an experimental investigation of a mechanical power-take-off (PTO)

A biomimetic surface for water collection was successfully engineered using three-dimensional (3D) printing technology. The fused deposition modeling-type 3D printing was used to create a reusable mold. This was used to cast waveform microstructures on a hydrophobic polymer surface, which was induced by using stacked filaments. The etching was performed on the printed mold by using a chemical solvent

The use of printed circuit boards (PCBs) has become essential in manufacturing parts with electronic functions. However, the placement of PCBs inside a product requires special plates or fixtures that need to be separately designed, fabricated, and assembled. In addition, PCB manufacturing generally utilizes various toxic metals and etchants. Thus, there is a need to address the issues of space, cost

Surface texturing on cutting tools has a great influence on reducing the friction force between tool and chip interfaces. In this study, a grinding method was developed to fabricate micro-groove textures on cutting tools using a special diamond grinding wheel on the tool rake face. A comparative experiment was done using a laser and other grinding method to fabricate micro-grooves. The developed grinding

The Rehbinder effect (R-effect) on microcutting has been successful to augment machinability of ductile metals; however, there is a lack in understanding of its influence on texture evolution in the machined surfaces. This study validates the R-effect on AA6061-T6 and characterises the influence of the R-effect on the texture transformation in the machined surface. Microhardness tests reveal that the

Waste electrical and electronic equipment (WEEE) not only occupies resources but also pollutes the environment. Disassembly and recycling of WEEE is an important part of sustainable manufacturing. However, the number of parts in WEEE is large and the relationship between parts is complex, which increases the difficulty of disassembly task planning. Therefore, this paper proposes a precedence graph

Recently, good interest in renewable energy has been increased and thereby the need for noise prediction model is required for the design of wind turbines with less noise. In particular, trailing edge noise is a major noise source. A number of results using complex predictive models with machine learning techniques and artificial neural network have been reported, and the results are generally good

We develop a facile and eco-friendly airbrush-based method for the fabrication of gas diffusion layers (GDLs) with improved water removal characteristics for high-performance polymer electrolyte membrane fuel cells (PEMFCs). The GDL architecture airbrushed on a porous carbon paper uniquely comprises hydrophobic double-layer coating and fine-patterned hydrophilic channels, which facilitate the outbound

In the last decades, numerous mechanical energy sources have been utilized as primary energies to produce electricity by using different energy harvesting technologies, such as electromagnetic, and piezoelectric technologies. Among these mechanical energy sources, fluid flow energy, defined by water flow and airflow energies, is one of the most important and wide-used renewable energy sources, which

This paper proposes the solution to reduce the energy consumption of forming machine for the composite stringer manufacturing by applying the lean manufacturing techniques. The lean techniques such as standard operating procedures, single minute exchange of dies, external set-up based on production efficiency improvement are used to optimize the stringer manufacturing process. The improved set-up is

The triboelectric nanogenerator (TENG) is in the spotlight due to its advantages of material and processing diversity. Despite these advantages, for its practical utilization, the output performance of the TENG still needs to be enhanced. Unlike most of the previous approach to increase triboelectricity between two contact surfaces, in this paper, the output performance is significantly enhanced by

The ever-increasing CO2 emission has necessitated the search for suitable technologies for CO2 utilization at a low cost. Recently, a novel concept called reactive gas electrosorption (RGE) for energy harvesting from CO2 emission, which could boost the efficiency of a thermal power plant by 5% was proposed by Hamelers and coworkers. The concept involves mixing of air stream with a low CO2 concentration

Automatic design of the number of sample points and sample locations when measuring surfaces with different geometries is of critical importance to enable autonomous manufacturing. Uniform sampling has been widely used for simple geometry measurement, e.g. planes and spheres. However, there is a lack of appropriate sampling techniques that can be applied to complex freeform surfaces, especially those

Strong thermal–mechanical coupling and rapid tool failure easily occur in the milling process of hardened steel with solid end mills. This work investigates the effectiveness of minimum quantity lubrication (MQL) during high-speed milling of hardened mold steel. Three kinds of spraying modes were designed in the experiment. They are namely the spraying ways to the flank face (MQL-F), to the rake face

In recent years, triboelectric nanogenerator (TENG) has been proven to be an effective and simple solution for self-powered wearable sensing, and a wide variety of materials and methods have been applied to TENG based sensors. In this study, an ultrathin fiber film with nanoporous brain-like structure (BUF) was obtained by cold-pressing the electrospun biocompatible fiber mats, and a wearable TENG

We survey various state-of-the-art methods for welding magnesium alloys and steels using different joint configurations. Microstructural characterizations indicate that four microstructures may form at the Mg/steel interface after welding: unwelded gap, metal oxides, solid solutions, or intermetallic compounds. Reaction products at the Mg/steel interface vary with different welding methods, alloying

This paper deals with a new development of a swash-plate hydraulic pump. It is particularly designed to aim its usage in applications where environmental impacts should be concerned. Thus, the pump is based on not mineral-based oil but simple tap water. The Electro-Hydraulic Actuator (EHA), a linear motion generator operated by an electric motor installed to the proposed pump, can be attractive and

The machining characteristics of glass substrates containing chemical components were investigated for the purpose of femtosecond laser helical drilling. A femtosecond laser of wavelength 1552 nm and pulse duration 800 fs was adopted in the laser machining system. The substrates investigated were aluminosilicate, soda-lime, and borosilicate glass. The chemical components contained in each glass substrate

This article presents the results of experiments concerning a computational fluid dynamics (CFD)/numerical analysis of the flow of air in the grinding zone during the sharpening of the face surface of hob cutters while using the MQL method. The carrying out of a simulation allows one to determine the influence of various settings of the angle of the spray nozzle on the amount of air directly reaching

High-power semiconductor laser cavities are formed via the cleavage plane, and critically influence the reliability and performance of the laser. This paper investigates both the scratching operation and the cleavage operation to improve the quality of the cleavage plane during the entire cleavage process. The scratching capability index (SCI) variable was proposed to evaluate the scratch quality of

During the dry post-machining processing of selective laser melting (SLM)-produced stainless steel with TiAlN coated tool, the elements of stainless steel chips can diffuse and adhere into the coated tool surface, causing serious adhesive wear. In this study, to inhibit the adhesion problem at the tool-chip interface, surface textures with different scales (micro-, nano- and micro/nano-textures) are

During the large-area EB irradiation, plasma generation is confirmed by collision of electrons with vaporized workpiece materials above the substrate surface due to its high energy density. This phenomenon would cause the sputtering of target material when it is set near the substrate surface. Thus, there is a possibility for coating a target material on the substrate surface by the large-area EB irradiation

The eco-efficiency of actual production processes is still one dominating research area in engineering. However, neglecting the environmental impacts of production equipment, technical building services and energy supply might lead to sub-optimization or burden-shifting and thus reduced effectiveness. As an established method used in sustainability management, Life Cycle Assessment aims at calculating

A bimetallic ring component is forged by a friction stir assisted forging (FS-forging). A cylindrical bimetallic blank, magnesium AZ31 cylinder (Mg core) tightly fitted inside an aluminum 6061-T6 tube (Al skin), is used. In the FS-forging, the frictional heat and stirring of rotating tool forge the blank into a desired shape, while simultaneously generate a solid-state joint between the Mg core and

Laser additive manufacturing has been regarded as a typical green manufacturing process. This paper presents a novel numerical approach termed time step fusion (TSF) along with the finite volume method (FVM), for fast computing the temperature field in a predominant laser additive manufacturing process, namely, selective laser melting. The solution acceleration strategy using TSF is that the entire

During the past two centuries, due to too fast growth of the human population, the pollution made by human has seriously impacts on our environment, particularly, for the CO2 emission. To diminish the CO2 emission problem, one of the effective solutions is applying lightweight material, such as the fiber-reinforced plastics (FRP), to replace metal in the manufacturing of transportation vehicles. However

Living tissues in the body receive various types of stimuli, including mechanical strain, pressure, and varied chemical environments. In contrast, conventional cell cultures are processed under in vitro conditions, which are not similar to the actual body’s environment. To precisely simulate the human body environment, a dynamic cell culture device capable of applying mechanical stimulation to cells

The display industries recently demand new microscale dot-type patterns for thinner and brighter displays with high energy efficiency, which are randomly distributed with irregular separation distances and have uniform optical characteristics. We developed a new program to generate the coordinates of the controlled microscale random patterns considering their diameter and the distance to the nearest

Lean Manufacturing tool promises product quality and assures the effective way of product production and processing. This research provides continuous involvement of lean manufacturing in all stages of the production process in identifying and eliminating waste. Electrical components manufacturing involves hazardous chemical powder molding at high pressure to produce electrical switches and switchboards

The global transport sector is heavily dependent on fossil fuels as a vital source of energy. This has adversely affected the climate. This climate change necessitates that technologies employing renewable and clean energy should be utilized in the global transportation sector. To address this issue, in this study, a small wind turbine was implemented on a vehicle, such that it is able to capture the

The polymer electrolyte membrane fuel cell has been widely studied in many fields and is being commercialized through various applications such as automobiles or distributed power generation. However, there are some fuel-cell operation stability and durability issues yet to be solved. One such problem is how to monitor the hydration condition within a fuel cell quickly and precisely for fault detection

Ti–6Al–4V components fabricated by laser powder bed fusion (LPBF) suffer from high brittleness and poor toughness issues, which are largely attributed to the \({\alpha }^{^{\prime}}\)-martensite phase of LPBF products. Post-heat treatment is often carried out to improve the toughness of LPBF products, which, however, has been reported to result in a decrease in strength, abrasion resistance, and corrosion

A method based on piezoelectric and magnetostrictive coupling inverse effect to generate precise controllable force is proposed to meet the requirement of manipulation force control in ultra-precision machining and assembly process. According to the principle of magnetic flux continuity, combine with the characteristics of piezoelectric and magnetostrictive inverse effects, the working mechanism of

Colloidal semiconducting nanocrystals, also called colloidal quantum dots (QDs) afford efficient photoconversion from visible to infrared wavelength owing to their size-dependent optoelectronic properties. To manufacture the highly performing devices utilizing colloidal NCs, however, unreacted impurities should be removed following synthesis. As the scale of NCs synthesis increases, especially in industry

The affiliation of the first author, Prof. Hyeon-Seop Yi has been changed to.

One of the major issues of drilling operations pertains to the formation of burrs, which greatly influences the accuracy of the manufactured parts, and, thus, the capability to meet the desired performance of the part. To remove or prevent these burrs, their geometry must be measured accurately, even though they are sharp and irregular in shape. The accurate measurement of the geometry of a burr will

Due to the intrinsically limited mechanical properties, functionalities and structures of mineral material composites (MMCs) made through traditional fabrication approaches, there is a critical need to develop novel three dimensional (3D) forming techniques that can construct mineral material composites (MMCs) and structures with high performance and functionalities. The direct ink writing (DIW), as

Polypropylene (PP) nanocomposite films reinforced with surface-modified nanoclay, maleic anhydride-grafted PP (PP-g-MA), and surfactants, such as cetyl-trimethyl-ammonium bromide (CTAB) and octadecyl-trimethyl-ammonium bromide (ODAB), were fabricated by extrusion, and the effect of surfactant type used for the nanoclay and the take-up speed of extrusion on the mechanical properties and crystallinity