Flexible Movement Research Articles

A Miniaturized Capsule Endoscope Equipped a Marking Module for Intestinal Tumor Localization.

This study introduces a miniaturized capsule endoscope equipped with a marking module for intestinal tumor or lesion localization. The design concept is based on an active wireless capsule endoscope platform that is manipulated by an external electromagnetic actuation (EMA) system. The magnetic response of a permanent magnet inside the capsule is designed to have flexible movement in viscous environment of bowel. This magnet is also utilized to activate tattooing process by triggering a gas-generated chemical reaction. Once approaching to a target region, gradient magnetic field from EMA system is induced to push magnet down, releasing water to dry chemical powder mixture. Then the gas pressure increases and pushes the piston move to inject ink into target point. During traveling in digestive organs, injection needle is stowed inside the capsule to avoid damage to the organs. The whole procedure is manipulated by EMA system, the injection consumes no internal battery and is observable through capsule's camera which provides clinician vision. Basic tests were conducted to evaluate the performance of proposed robotic capsule. The success of creating a black visible bled from serosa of intestine proves the feasibility and potential of the design. This study could be an alternative for traditional tattooing endoscopy and motivate other research groups for further development of functional wireless capsule endoscope.

Differential contributions of striatal dopamine D1 and D2 receptors to component processes of value-based decision making.

Dopamine has been implicated in value-based learning and decision making by signaling reward prediction errors and facilitating cognitive flexibility, incentive motivation, and voluntary movement. Dopamine receptors can roughly be divided into the D1 and D2 subtypes, and it has been hypothesized that these two types of receptors have an opposite function in facilitating reward-related and aversion-related behaviors, respectively. Here, we tested the contribution of striatal dopamine D1 and D2 receptors to processes underlying value-based learning and decision making in rats, employing a probabilistic reversal learning paradigm. Using computational trial-by-trial analysis of task behavior after systemic or intracranial treatment with dopamine D1 and D2 receptor agonists and antagonists, we show that negative feedback learning can be modulated through D2 receptor signaling and positive feedback learning through D1 receptor signaling in the ventral striatum. Furthermore, stimulation of D2 receptors in the ventral or dorsolateral (but not dorsomedial) striatum promoted explorative choice behavior, suggesting an additional function of dopamine in these areas in value-based decision making. Finally, treatment with most dopaminergic drugs affected response latencies and number of trials completed, which was also seen after infusion of D2, but not D1 receptor-acting drugs into the striatum. Together, our data support the idea that dopamine D1 and D2 receptors have complementary functions in learning on the basis of emotionally valenced feedback, and provide evidence that dopamine facilitates value-based and motivated behaviors through distinct striatal regions.

DESIGN AND CONTROL OF SPIDER ROBOT MODEL

Robots imitating spider’s moving have many advantages such as flexible movement, high stability, diversity in movements performed, especially in terrain crossing, in military reconnaissance, in surveying and collecting environmental data in dangerous areas,.... In this article with the main objective is to exploit multiple control methods to support applications of a spider robot with low-cost, a spider robot with 6 legs and 18 joints was designed. The ESPWROOM-32 module (ESP32-D0WDQ6 chip) and MIT App Inventor were used as the main tools for conducting this research. As a result, the robot is controlled via Bluetooth and Wifi to move, making some actions by self-written software running on the Android operating system. In addition, the robot has the capacity of self-propelled to avoid simple obstacles and send some environmental parameters to the software, including obstacles distance, humidity and temperature.

Enhanced flexibility and environmental durability of copper electrode produced with conductive ink containing silane coupling agents with diamine and ether spacer

Cu-based conductive inks are more cost effective than silver-based ones for flexible electronics. However, it is challenging to simultaneously ensure the mechanical flexibility, environmental oxidation durability, and low resistance of the sintered Cu electrodes. To achieve this goal, Cu-based conductive inks including silane coupling agents are developed and used to produce flexible Cu electrodes on cellulose paper after air–atmosphere sintering. The key factor to achieve the mechanical flexibility and environmental oxidation durability at the same time is the use of aminoethyl-aminopropyltrimethoxysilane (AEAPTMS) or 3-glycidoxypropyltrimethoxysilane (GPTMS). Negligible resistance change is observed in the sintered Cu electrode with AEAPTMS, even after 1000 repeated bending cycles with a bending radius of 5 mm and exposure at 60 °C/80% RH for 7 days. Especially, Cu electrodes produced using GPTMS show improved flexibility with negligible resistance change even after 10,000 bending cycles. To demonstrate the applicability of these Cu electrodes, a flexible paper-based movement sensor is successfully fabricated from the present Cu-based ink. This approach using silane coupling agents will contribute to the reliable operation of Cu-based flexible devices with high mechanical and environmental durability.

Kinematics of Stewart Platform Explains Three-Dimensional Movement of Honeybee's Abdominal Structure.

The Stewart platform is a typical parallel mechanism, used extensively in flight simulators with six degrees of freedom. It is rarely found in animals and has never been reported to regulate and control physiological activities. Now an equivalent Stewart platform structure is found in the honey bee (Hymenoptera: Apidae: Apis mellifera L.) abdomen to explain its three-dimensional movements. The stereoscope and scanning electron microscope are used to observe the internal structures of honeybees’ abdomens. Experimental observations show that the muscles and intersegmental membranes connect the terga with the sterna and guarantee the honey bee abdominal movements. From the perspective of mechanics, a Stewart platform is evolved from the lateral connection structure of the honey bee abdomen, and the intrasegmental muscles between the sternum and tergum function as actuators between planes of the Stewart platform. The extraordinary structure provides various advantages for a honey bee to complete a variety of physiological activities. This equivalent Stewart platform structure can also be used to illustrate the flexible abdominal movements of other insects with the segmental abdomen.

Coherent perfect absorber with independently tunable frequency based on multilayer graphene

We propose two terahertz coherent perfect graphene-based absorbers that can simultaneously realize the tunable resonant frequency and absorption. The Fermi energy of graphene, which can be changed by applied electric fields affect the frequency of absorption peaks. By adjusting the phase difference between two interfering beams, the absorption intensity can be controlled. The simulated results indicate that the absorptivity can achieve nearly 100% change and the adjusting range of absorption frequency is up to 16 THz. With the flexible movement of four absorption peaks, the absorption bandwidth over 90% can be extended to 10 THz. What is more, this paper displays the application to photoswitch by phase modulation. In particular, the proposed absorbers are polarization-insensitive and almost omnidirectional. We hope that our results can provide substantial help for the potential applications in the future metamaterial devices.

Electrical behaviour of nanosilver doped gallium flexible conductor for biomedical application

In the biomedical field, continuous researches have been expanding on doping of metals to acquire new materials for flexible conductors. Flexible conductors have been rapidly sought in several biomedical applications such as biosensors, implants, prostheses, etc. For example, prostheses are to mimic the movement of the human body which enables flexible and repetitive movement. However, these alloys functions hampered due to fatigue or loss of conductivity when subjected to bending. To address such issue, gallium is a potential solution as it has high ductility. However, gallium has relatively low electrical conductivity. In order to enhance the conductivity, nanosilver was used to doped as silver has the highest electrical conductivity. Moroever, nanosilver enables better diffusibility into the gallium matrix. In this research, for doping process, gallium and nanosilver were mixed at six different ratios, which were Ga:Ag of 1:1, 2:1, 3:1, 4:1, 5:1 and 6:1. It is revealed that higher concentration of gallium to nanosilver provides better diffusion, and better electrical behaviour. It is also revealed that the Ga:Ag of 3:1 is the most effective concentration in terms of better homogeneity and lower electrical resistance. Such findings are crucial for proper doping process and considered as the founding parameters for better alloy formation. Nevertheless, these findings would also contribute to biomedical research industry especially for artificial organ through developing new alloy materials.

A Multi-module Controller for Walking Quadruped Robots

Motion control based on biologically inspired methods, such as Central Pattern Generator (CPG) models, offers a promising technique for robot control. However, for a quadruped robot which needs to maintain balance while performing flexible movements, this technique often requires a complicated nonlinear oscillator to build a controller, and it is difficult to achieve agility by merely modifying the predefined limit cycle in real time. In this study, we tried to solve this problem by constructing a multi-module controller based on CPG. The different parallel modules will ensure the dynamic stability and agility of walking. In the proposed controller, a specific control task is accomplished by adding basic and superposed motions. The basic motions decide the basic foot end trajectories, which are generated by the predefined limit cycle of the CPG model. According to conventional kinematics-based design, the superposed motions are generated through different modules alter the basic foot end trajectories to maintain balance and increase agility. As a considerable stability margin can be achieved, different modules are designed separately. The proposed CPG-based controller is capable of stabilizing a walking quadruped robot and performing start and stop movements, turning, lateral movement and reversal in real time. Experiments and simulations demonstrate the effectiveness of the method.

Evaluation of the Effect of Bioresorbable Plates and Screws in the Treatment of Condylar Fractures, Assisted by Digital Preoperative Planning

Although bioresorbable materials have begun to be applied in the clinic, they are used primarily in children with fractures; thus, there are few reports of their application for treatment of condylar fractures. This study evaluated the effect of the application of bioresorbable plates and screws for patients with condylar fractures, assisted by digital preoperative planning. This was a prospective interventional study. The sample was composed of 46 patients treated at the School of Stomatology of the China Medical University (Shenyang, China) from October 2016 through May 2018 for condylar fractures alone or in combination with other facial fractures. All patients underwent confirmatory preoperative computed tomography (CT) to obtain Digital Imaging and Communications in Medicine (DICOM) format data for preoperative designing. By digital designing, the authors confirmed operative plans for each patient. All 46 patients underwent bioresorbable osteosynthesis and underwent repeat CT on postoperative day 3. Postoperative clinical assessments included postoperative positions of the fracture segments, maximal mouth opening, lateral excursion movements, occlusal status, and patient satisfaction. These variables were used to assess postoperative efficacy. The sample was composed of 46 patients who had open reduction with internal fixation on 52 sides. At the 3-month follow-up visit, the proportions of patients who were satisfied with the results and who achieved stable occlusion, appropriate maximal mouth opening, and flexible lateral excursion movement were 97, 100, 66, and 95%, respectively. One patient sustained postoperative displacement of a condylar fracture fragment, as confirmed by repeated CT. He was lost to follow-up at 3months postoperatively. The results of this study suggest that open reduction treatment of condylar fractures implanted with bioresorbable materials in combination with digital preoperative designing is an effective method for managing patients in clinical practice.

Design of Obstacle Avoidance Mechanism of Magnetic Levitation Type Inspection Robot for High Voltage Lines

An obstacle avoidance mechanism is designed for the operation mode and the overall structure of high-voltage power lines inspection robot based on magnetic levitation principle. The mechanism is composed of a planar linkage mechanism and a screw nut mechanism with two degrees of freedom. Through the control of two of the original, the robot has a function of opening the shell and obstacle avoidance. The mechanism is simple and occupies less space with flexible movement, compact structure, to meet the requirements of obstacle avoidance to avoid vibration hammer, clamp, straight line towers and other obstacles effectively which solved the contradiction between the small space in the robot and the obstacle avoidance requirements. Two prime bar linkage relationships is obtained according to static analysis of the mechanism. Finally, by means of Kinematics simulation of the obstacle process through Pro/E software, the feasibility of the institution obstacle scheme is verified.

Creating Flexible Movement

Creating Flexible Movement

Condensing-enriched magnetic photonic barcodes on superhydrophobic surface for ultrasensitive multiple detection.

The ultrasensitive detection of multiple nucleic acids has great significance in a broad range of medical fields since nucleic acid samples are usually of small volumes and highly diluted. Herein, we present a novel magnetic photonic crystal (PhC) barcode-integrated condensing-enriched superhydrophobic platform for the ultrasensitive multiple miRNA detection. Droplets containing targets could suck the hydrogel PhC barcodes without losing their targets due to the difference in wettability between the hydrophilic PhC barcodes and hydrophobic substrate. During the evaporation of water from the droplet microreactors, these targets could be effectively enriched in the barcodes for achieving higher sensitivities. As the encoding signals of the PhC barcodes are the characteristic reflection peaks generated by their ordered physical nanostructures, the barcodes are stable and free from any fluorescent background and photobleaching; thus, they are accurate for distinguishing different targets. In addition, with the integration of magnetic nanoparticles into the hydrogel PhC barcodes, they could be imparted with the features of immobilization during change of medium and flexible movement for controlling the reaction, both of which could facilitate the detection processes. Based on this platform, we have demonstrated that the detection limit of multiple miRNAs is improved by about three orders. Thus, our platform is an ideal alternative for the ultrasensitive simultaneous multiplex analysis in medical fields.

Cyclical Balanced Development of Economy and Society for Full Employment and National Happiness

The ultimate goals of the economy are full employment and promoting the happiness of the people. This paper analyzes empirically the failures to achieve full employment and national happiness promotion despite long-term economic development in the economic policies of liberal, socialist, and socio-democratic regimes. It is emphasizing unused resources such as chronic unemployment and surplus of capital as the main reasons for these failures. To fulfill these main purposes, a cyclical equilibrium development model of economy and society is suggested here. The roles of civilians are also stressed to complement the failures of the market and governments. And To achieve the flexible movement of labor and the complete use of surplus labor and excessively accumulated capital, the monopolization of the markets, governments, and civil bodies including large unions of labor and professional occupations must be removed. The employment of workers with relatively weak labor abilities is contributory to enhancing national happiness by increasing social as well as economic value especially in the period of economic depression. Policy directions and several measures including deregulation of markets, the punitive taxations on the preventions of labor mobility and excessive replacement of labor with capital intensive methods, and the expansion of social enterprises are also provided to enable the model to be applied in Korea.

Performance Evaluation of a Magnetically Actuated Capsule Microrobotic System for Medical Applications.

The paper aims to propose a magnetic actuated capsule microrobotic system, which is composed of a magnetically actuated microrobot with a screw jet mechanism, a driving system, and a positioning system. The magnetically actuated microrobot embedded an O-ring magnet as an actuator has potential for achieving a particular task, such as medical diagnose or drug delivery. The driving system composes of a three axes Helmholtz coils to generate a rotational magnetic field for controlling the magnetically actuated microrobot to realize the basic motion in pipe, e.g., forward/backward motion and upward/downward motion. The positioning system is used to detect the pose of the magnetically actuated microrobot in pipe. We will discuss the shape of the Helmholtz coils and the magnetic field around the O-ring magnet to obtain an optimal performance of the magnetically actuated microrobot. The experimental result indicated that the microrobot with screw jet motion has a flexible movement in pipe by adjusting the rotational magnetic field plane and the magnetic field changing frequency.

Crystal structure and functional characterization of a cold-active acetyl xylan esterase (PbAcE) from psychrophilic soil microbe Paenibacillus sp.

Cold-active acetyl xylan esterases allow for reduced bioreactor heating costs in bioenergy production. Here, we isolated and characterized a cold-active acetyl xylan esterase (PbAcE) from the psychrophilic soil microbe Paenibacillus sp. R4. The enzyme hydrolyzes glucose penta-acetate and xylan acetate, reversibly producing acetyl xylan from xylan, and it shows higher activity at 4°C than at 25°C. We solved the crystal structure of PbAcE at 2.1-Å resolution to investigate its active site and the reason for its low-temperature activity. Structural analysis showed that PbAcE forms a hexamer with a central substrate binding tunnel, and the inter-subunit interactions are relatively weak compared with those of its mesophilic and thermophilic homologs. PbAcE also has a shorter loop and different residue composition in the β4–α3 and β5–α4 regions near the substrate binding site. Flexible subunit movements and different active site loop conformations may enable the strong low-temperature activity and broad substrate specificity of PbAcE. In addition, PbAcE was found to have strong activity against antibiotic compound substrates, such as cefotaxime and 7-amino cephalosporanic acid (7-ACA). In conclusion, the PbAcE structure and our biochemical results provide the first example of a cold-active acetyl xylan esterase and a starting template for structure-based protein engineering.

Novel phosphoric acid (PA)-poly(ether ketone sulfone) with flexible benzotriazole side chains for high-temperature proton exchange membranes

Poly(ether ketone sulfone)s with functionalized benzotriazole side chains are simply designed and successfully obtained by the copolycondensation of 4,4-difluorodiphenylsulfone, 4,4’-dihydroxydiphenylamine and a benzotriazole-based difluoro compound. The resulting polymers are identified by Fourier transform infrared spectroscopy and nuclear magnetic resonance, and the results are consistent with the proposed polymer structures. Owing to the intermolecular hydrogen bonding, the phosphoric acid (PA)-doped polymer membranes show encouraging mechanical properties. Taking advantage of the flexible movement of the benzotriazole in the side chains, the resulting membranes exhibit promising proton conductivities and fuel cell performance, which makes them a strong potential material for applications in high-temperature proton exchange membrane fuel cells. Taking advantage of the flexible movement for the benzotriazole in the side chains, the resulting membranes exhibit encouraging proton conductivities and fuel cell performance.

Research on The Control System of The Friendly Walking Assistant Robot for The Elderly

With the intensification of aging population, medical and social insurance system is facing up with the unprecedented pressure. Most of old people need nursing and care. On the one hand, it needs expensive expenditure and manpower. On the other hand, living quality of old people in degree of freedom is greatly reduced. The problem of helping old people to walk has become a great social problem. The self-adaption coordination control of robot is an important indicator of walking assistant robot for the elderly and also the precondition to support and protect old people and the disabled. In order to realize the control of direction for walking assistant robot and get the smaller turning radius and more flexible movement, this paper studied a dual-motor differential control method to realize forward, backward, and cornering of robot. Finally, the experimental results show that the control system of the friendly walking assistant robot for the elderly is rational and feasible, and the designed control system is stable and reliable.

Four-legged robot design and gait planning

This paper proposes a new type of hybrid leg mechanism based on a five-bar mechanism. The single leg has three degrees of freedom. The positive and negative solutions of the leg mechanism are analyzed theoretically and solved with MATLAB. The gait planning choose diagonal gait. ADAMS is used to verify the centroid displacement and foot displacement of each leg of the gait planning. This model is proposed based on series-parallel mechanism. The mechanism not only increases the movement space and improves the carrying capacity, but also has the advantages of simple control and flexible movement. This research lays a theoretical foundation for later experiments.

Multiple Coordinated Views at Large Displays for Multiple Users: Empirical Findings on User Behavior, Movements, and Distances.

Interactive wall-sized displays benefit data visualization. Due to their sheer display size, they make it possible to show large amounts of data in multiple coordinated views (MCV) and facilitate collaborative data analysis. In this work, we propose a set of important design considerations and contribute a fundamental input vocabulary and interaction mapping for MCV functionality. We also developed a fully functional application with more than 45 coordinated views visualizing a real-world, multivariate data set of crime activities, which we used in a comprehensive qualitative user study investigating how pairs of users behave. Most importantly, we found that flexible movement is essential and-depending on user goals-is connected to collaboration, perception, and interaction. Therefore, we argue that for future systems interaction from the distance is required and needs good support. We show that our consistent design for both direct touch at the large display and distant interaction using mobile phones enables the seamless exploration of large-scale MCV at wall-sized displays. Our MCV application builds on design aspects such as simplicity, flexibility, and visual consistency and, therefore, supports realistic workflows. We believe that in the future, many visual data analysis scenarios will benefit from wall-sized displays presenting numerous coordinated visualizations, for which our findings provide a valuable foundation.

Four-dimensional calibration turntable of the motional Stark effect diagnostic on EAST.

The motional Stark effect (MSE) diagnostic is applied to measure the safety factor q and current density profile of a tokamak device, which are important parameters in realizing the high-performance and long-pulse steady state of a tokamak. A single-channel MSE diagnostic based on dual photoelastic modulators, whose sightline meets with the neutral beam injection at a major radius of R = 2.12 m, has been built for the D window of the Experimental Advanced Superconducting Tokamak (EAST). According to the requirements of MSE diagnostic polarimetric calibration, a high-precision four-dimensional calibration turntable, driven by four stepping motors and controlled by software running on the computer, was designed for EAST. The turntable allows us to rapidly calibrate the MSE diagnostic in a series of positions and angles during EAST maintenance. The turntable can move in four dimensions of translation, yaw, pitch, and roll of the polarizer and can create linearly polarized light at any given angle with accuracy of ∼0.05° for the MSE system offline calibration. The experimental results of the MSE diagnostic calibration in the laboratory show that the turntable has the advantages of high positioning accuracy, flexible spatial movement, and convenient control and fully meets the calibration requirements of an MSE diagnosis system.