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A laparoscopic hysterectomy has been highlighted to early diagnose uterine and cervical cancers. Reflecting these needs, commercial uterine manipulators employing a kinematic linkage system without mechanical actuators have been developed. None of them have achieved versatile movements, enabling anteversion and retroversion articulation of the uterus together with translational motion. More recently, motorized uterine manipulators capable of versatile and multifunctional movements are proposed. They have shown a strong potential to alleviate the burdens that gynecological surgeons can experience. Building on these concepts, we propose a master–slave system-based uterine manipulation robot (UMaRo). The device features a simple mechanism with a larger workspace, achieved by combining translational motion together with roll and pitch motions. The UMaRo also has an ergonomically designed uterus-shaped handle which enhances ease of use and convenience during procedures. More importantly, the master–slave system enables surgeons to operate the manipulator with less force, thereby reducing operator fatigue. A linkage mechanism allows the UMaRo to accommodate a higher load capacity, a larger workspace, and makes the device simpler. Numerical analyses are performed to determine the specifications of the UMaRo. Based on the results, the UMaRo is designed and fabricated. Then, experiments are performed in a phantom uterus model to validate the UMaRo performance. Results demonstrated a lifting force of 13 N in the pitch motion and 45 N in the roll motion, and the movement of the master–slave system was found to be well-synchronized out–inside of the phantom.

Solid oxide fuel cells (SOFCs) are efficient energy conversion devices that convert chemical fuels such as hydrocarbons directly into electricity. In particular, at the anode of SOFCs an oxidation reaction of the fuel occurs. These fuels contain impurities including hydrogen sulfide, which can strongly contaminate the electrodes and thus degrade SOFC performance. Although developing a catalyst with high sulfur-poisoning resistance is inevitable, to this point the detailed mechanism of how sulfur poisoning occurs is still unclear. In this study, with the motivation of improving the conventional Ni/YSZ catalyst, we investigated the mechanism of sulfur poisoning on a variety of Ni-based alloy surfaces using density functional theory (DFT) calculations. The effects of alloying transition metals (Cu, Rh, Pd, Ag, Pt, and Au) into Ni stepped surfaces on the adsorption of intermediates and on the activation barriers during the H2S decomposition reaction were elucidated in order to suggest a way to alleviate this sulfur deposition. Our results will provide useful insights into the design of sulfur-tolerant SOFC anode materials in the future.

A progressive motile sperm sorting device with a diffuser-type microfluidic channel is proposed to improve fertilization in assisted reproductive technologies. When sperm cells swim against a fluid flow, they are positioned according to their motility in specific channel zones. A numerical simulation is carried out in a meso-sized diffuser-type channel which can realize high throughput to verify the working principle and the sorting device is fabricated based on the simulation result. Furthermore, to analyze the condition of the semen and investigate the experimental results, a novel image processing method is proposed. With the proposed analyzing technique, the sperm sorting experiment is performed in the channel using the canine semen sample. As a result, the %motility increases from 59.89 to 69.36%, however, it does not satisfy the reported guideline for canine sperm motility (%motility > 70%). Therefore, we perform a washing process by injecting DPBS fluids to improve indexes related to motility. After double washing procedures, we could increase %motility from 59.89 to 82.24%, motile sperm rate from 33.38 to 53.10% and motility index from 26.35 to 49.44 in Zone A, comparing to the prepared sample.

Sulfur compounds in fuels deactivate the surface of anode materials in solid oxide fuel cells (SOFCs), which adversely affect the long-term durability. To solve this issue, it is important to design new SOFC anode materials with high sulfur tolerance. Unfortunately, it is difficult to completely replace the traditional Ni anode owing to its outstanding reactivity with low cost. As an alternative, alloying Ni with transition metals is a practical strategy to enhance the sulfur resistance while taking advantage of Ni metal. Therefore, in this study, we examined the effects of transition metal (Cu, Rh, Pd, Ag, Pt, and Au) doping into a Ni catalyst on not only the adsorption of H 2 S, HS, S, and H but also H 2 S decomposition using density functional theory (DFT) calculations. The dopant metals were selected rationally by considering the stability of the Ni-based binary alloys. The interactions between sulfur atoms produced by H 2 S dissociation and the surface are weakened by the dopant metals at the topmost layer. In addition, the findings show that H 2 S dissociation can be suppressed by doping transition metals. It turns out that these effects are maximized in the Au-doped Ni catalyst. Our DFT results will provide useful insights into the design of sulfur-tolerant SOFC anode materials.

We stress that the extraordinarily large adsorption energy and the large charge transfer to the adsorbate for the glucose adsorption structure of Ref. [1] are the results of adsorption of a C6H1O6 molecule rather than the adsorption of a glucose molecule. We report the glucose adsorption structure, the effect of Ni clusters on the adsorption energy of glucose, and the charge distribution for the glucose/Ni13/Gr system.

Gas-in-place (GIP) is a significant parameter in the assessment of gas resources and reserves, design of production strategy, and enhanced gas recovery. To precisely estimate GIP of shales, a direct method often sums experimentally measured desorbed gas by canister desorption testing (CDT), predicted lost gas in the recovery of the fresh core via CDT data in situ on the surface, and measured residual gas in the lab. However, the critical kinetic emission behavior remains poorly understood. A series of CDTs were collected from our previous work on 33 fresh shale cores. This work, based on experimental observation, proposes a Quasi-Langmuir model, which well fits the experimentally measured data with a coefficient of determination, R 2 , up to 0.9992. We also compare the model to 5 other potential kinetic gas sorption models, including Pseudo First Order (PFO), Bangham, Elovich, Ritchie, and Pseudo Second Order (PSO) models in terms of the proposed relationship between changes of emitted gas and time. Results show that the Quasi-Langmuir model fits the kinetic data best, followed by Bangham, Ritchie, PSO, PFO, and Elovich models. Ritchie and PSO models give comparable fittings, and the Elovich model deviates from measured data far more than other models. This work improves understanding of the emission behavior and process of shale gas in CDT, which will provide a robust estimation of lost gas in the borehole, and a more accurate GIP estimate for production in the petroleum industry. Results from this work have significant implications for monitoring the treatment of water and air contamination based on adsorption.

Although previously developed Dielectrophoresis activated cell sorters (DACSes) have achieved high separation efficiency, limitations still exist with respect to the low throughput. In this paper, therefore, a numerical analysis is presented for a novel DACS to achieve not only high efficiency but also high throughput. Additionally, experimental validation is performed based on the results of a numerical simulation. First, streamlines in the channel are investigated according to various flow rate ratios in each outlet. After cells are deflected by a sufficient amount of dielectrophoretic force, they arrive at the tip of the last electrode pair. Their movement is then determined by hydrodynamic force. Therefore, it is important to confirm whether or not the streamline at the tip of the last electrode pair connects to the target area. Based on the streamline analysis results, the particle trajectory under various AC electric fields is investigated using a three-dimensional analysis. Accordingly, an input voltage condition (7 Vp-p at 10 kHz) is selected to confirm the influence of dielectrophoretic force. Conclusively, optimal flow rates under the determined input voltage condition are selected as 10 μl/min and 20 μl/min in outlet A (target area) and outlet B (non-target area), respectively. In order to validate the feasibility of the selected flow rates, a separation test is performed employing a K562 cell–bone marrow cancer cell–as a target cell. In the experiment, the proposed DACS achieves a high throughput of 45000 cells/min as well as a separation efficiency of 96.5% and recovery rate of 47.25%.

Recently, arsenic trioxide (As 2 O 3 ) has been highlighted for use in chemotherapy drugs, and it has been reported that it can induce the apoptosis of a leukemia cell. Until now, methyl thiazol tetrazolium (MTT) assay, DNA fragmentation assay, and morphologic examination were typically employed to investigate the apoptotic rate of leukemia cell lines after being treated with arsenic trioxide. In this paper, we propose a novel dielectrophoresis activated cell sorter (DACS) to evaluate the apoptotic rate of leukemia cells. The proposed electrode arrays based DACS consists of two transparent plates with macro width. These arrays enable the improvement of throughput and achieve the minimum number of structures to enhance the performance of the sorter with respect to factors such as cell adhesion and the leaking phenomenon. In particular, to achieve high separation efficiency, five microelectrodes are repeatedly deposited on each glass plate. In order to generate a dielectrophoretic (DEP) barrier for cell separation, the microelectrodes facing each other on the two glass plates are exactly aligned in the fabrication process. To confirm the feasibility of this cell separation concept, we analyze the forces acting on the target cell, including the DEP force, hydrodynamic drag force, and gravity. In addition, we implement a simulation study for the proposed DACS with specific channel and electrode dimensions. Prior to the separation test, we select a leukemia cell (K562 cell) as our target cell and investigate the apoptotic rate of the K562 cells treated with the arsenic trioxide according to the duration of treatment. This provides us with the efficacy of As 2 O 3 for K562. Prior to the separation experiment for the efficacy evaluation, we first carry out a separation test with all live K562 cells and obtain a high separation efficiency of 94.74% with a low voltage of 7 Vp-p with 10 kHz. Then, the separation efficiencies are evaluated utilizing a live/dead cell mixture according to the duration of treatment being 12 and 24 h. Conclusively, the DACS achieves high separation efficiencies of 94.71% and 93.25% with the treated samples during 12 and 24 h durations, respectively. Moreover the recovery rate and the throughput show competitive results of 62.5% and 17,000 cells/min.

In this article, a cell sorter with a simplified structure is presented. This sorter harnesses negative dielectrophoretic (n-DEP) force and gravity. In order to enhance the throughput and recovery rate, a meso-sized (15 mm×40 mm×200 μm) channel assembled with two transparent plates and two side walls is employed. Since a complex structure would degrade the cell sorter’s performance due to the leaking phenomenon as well as cell adhesion, the structure of the proposed sorter is simplified by minimizing the number of components. In addition, microelectrode arrays are designed with five continuous microelectrode pairs. This configuration utilizes continuous separation at each electrode pair, thereby enabling greater separation efficiency. As the drag force, gravity and n-DEP force are the principal parameters of the cell sorter, they are evaluated around the DEP barrier. Subsequently, based on the numerical simulation and theoretical results, separation conditions are experimentally investigated. Consequently, 7 Vp-p at 10 kHz is selected as the input condition. In order to evaluate the cell sorter, K562 cells − cancer cells found in bone marrow − are selected for use as target cells. In the experiments, a separation efficiency of 94.74±0.77%, a throughput of 17,000 cells/min and a recovery rate of 49.42% are achieved.

Originally introduced by H. A. Pohl in 1951, dielectrophoretic (DEP) force has been used as a striking tool for biological particle manipulation (or separation) for the last few decades. In particular, dielectrophoresis activated cell sorters (DACSes) have been developed for applications in various biomedical fields. These applications include cell replacement therapy, drug screening and medical diagnostics. Since a DACS does not require a specific bio-marker, it is able to function as a biological particle sorting tool with numerous configurations for various cells [e.g. red blood cells (RBCs), white blood cells (WBCs), circulating tumor cells, leukemia cells, breast cancer cells, bacterial cells, yeast cells and sperm cells]. This article explores current DACS capabilities worldwide, and it also looks at recent developments intended to overcome particular limitations. First, the basic theories are reviewed. Then, representative DACSes based on DEP trapping, traveling wave DEP systems, DEP field-flow fractionation and DEP barriers are introduced, and the strong and weak points of each DACS are discussed. Finally, for the purposes of commercialization, prerequisites regarding throughput, efficiency and recovery rates are discussed in detail through comparisons with commercial cell sorters (e.g. fluorescent activated and magnetic activated cell sorters).