Papers by Keyword: Flexible

Abstract: Transparent flexible electrodes (TFEs) are extremely crucial for expanding flexible and wearable electronic devices. Silver nanowires (AgNWs) have been extensively investigated as an alternative to replace Indium Tin Oxide (ITO) as a commercial TFE due to their high conductivity, transparency, and flexibility. AgNWs have replaced ITO-based electrodes as the preferred approach in flexible, transparent, and conductive electrodes (FTCE). AgNWs outperform other materials, such as Reduced Graphene Oxide (RGO), ceramic material, Carbon Nanotubes (CNT), and conductive polymers, in terms of electrical conductivity, transmittance, flexibility, and low sheet resistance. Numerous techniques, including as electrospinning, spray coating, spin coating, and doctor blades, are used to use AgNWs as flexible substrates. Seed-based growth and template-assisted synthesis are two fundamental synthesis techniques that could be used to generate AgNWs. However, poor adhesiveness, and thermal and electrical stability, begin to be bottlenecks for AgNWs as high deployment in a variety of devices. So AgNWs synthesis process began to shift to other methods, such as wet chemical and polyol. In this paper, short and clear summary of various advances including post-treatment methods such as UV radiation, microwave, sonication, quenching, and so on is conducted to be one step forward to test mechanical properties and to improve AgNWs performance.

Abstract: Piezoelectric ceramics possess very high piezoelectric coefficients but lacks the conformability for using them in flexible devices, in high-resolution sensing devices that can be integrated to human skin and other such applications. This problem can be resolved by blending them in appropriate proportion with polymers which are intrinsically light weight, stable and flexible. In this paper polymer composites xPZT– (1-x) PVDF (x= 0, 0.025, 0.05, 0.10, 0.15, 0.20 and 0.25) were prepared by solution casting method and their dielectric and its mechanical properties were studied. Given that PZT has a very high dielectric value, the composite's dielectric constant grew as the filler concentration increased which shows better dipole alignment in the composite. With an increase in filler concentration, the composite loses flexibility and tensile strength. Due to their greater Young's modulus than pure PVDF film, the films with compositions x=0.025 and x=0.05 could have better piezoelectric characteristics.

Abstract: A high performance flexible temperature sensor for environmental and health monitoring has been fabricated using various combinations of composite blend of poly vinylidene fluoride / poly (3,4-ethylenedioxythiophene)-poly (styrenesulfonate) (PVDF/PEDOT:PSS). The response curves and working principle were investigated and sensors were then fabricated to achieve highly linear and stable response for a wide range of temperature sensing (25°C to 120°C). The film was fabricated on flexible polyethylene terephthalate (PET) substrate using spin coating. The copper electrodes were fabricated using copper tape. The sensors showed stable and close to linear response of impedance change by varying temperature in the range 25°C to 120°C. The resistance of the sensors changed from ~70MΩ to ~52MΩ for the temperature change in the range 25°C to 120°C. The sensors are aimed to replace low performance, complex and expensive sensors in the market for environmental and health monitoring applications.

Abstract: The available of conventional fuels are fluctuating depend on distribution from the source production to consumer. The availability of biogas as renewable energy is increasing due to establishments of many organic wastes processing worldwide. The need of electricity to support daily life activity is a must, but the availability of electric source in remote area is limited especially for a farm that far away from commercial line distribution of electricity. This work is dedicated to solve this problem. The single cylinder 4 stroke spark ignition engine (83 cc) was designed to be able to be fuelled flexibly by using biogas or liquefied petroleum gas (LPG), or gasoline if sometime the biogas not available during initiation of the process or during maintenance of anaerobic digester. The engine is still can be run to provide electricity by using conventional fuel such as LPG or gasoline. The full consumption as well as emission of this flexible fuel engine was investigated. It is found that the fuel consumption is 9.97 L/mint for Biogas, 0.004 L/mint for gasoline and 2.24 L/mint for LPG. Surprisingly by using biogas the emission of carbon monoxide (CO) was down to almost zero (0.02 ppm), comparing gasoline 0.32 ppm, and LPG 0.4 ppm.

Abstract: The focus of this study was to test a low-cost level plastic printer in the multi-material printing application using principles of design for additive manufacturing (DFAM). Two sample structures were designed in the project. One of the main planning principles of the examples was to integrate multiple functions into one part and intelligently utilize a variety of materials and reduce parts count. The most common material used in the experiments was the basic PLA, which is widely used, easy-to-print and economical alternative. As special materials, electrically conductive PLA-based graphene filament and highly flexible polyurethane-based filament was used. The results show that multi-material printing is also possible with lower cost devices and it makes it easier for smart products to be manufactured cost-effectively. It has also been found that multi-material printing can be technically challenging and that further research and experiments in this subject are needed. In the future, the research topic will be even more interesting as equipment and materials will develop. This paper presents detailed printing parameters for all the materials used in the printing tests.

Abstract: This paper presents results of the investigation of two biological role models, the shield bug (Graphosoma italicum) and the carnivorous Waterwheel plant (Aldrovanda vesiculosa). The aim was to identify biological construction and movement principles as inspiration for technical, deployable systems. The subsequent processes of abstraction and simulation of the movement and the design principles are summarized, followed by results on the mechanical investigations on various combinations of fibers and matrices with regard to taking advantage of the anisotropy of fiber-reinforced plastics (FRPs). With the results gained, it was possible to implement defined flexible bending zones in stiff composite components using one composite material, and thereby to mimic the biological role models. First small-scale demonstrators for adaptive façade shading systems – Flectofold and Flexagon – are proving the functionality.

Abstract: This paper explains the new design of the three wheel bike for post-stroke patients as a equipment for physical therapy. The bike can be pedaled by foot and / or by hand simultaneously. Bike frame is made of aluminum alloy pipe and consists of front and rear frame. The front frame is equipped with a steering system that can regulate the moving of two wheels of diameter of 22 ". The rear frame is equipped with a fold mechanism, shock breaker, seat and chain stay pipes for clamping the rear wheel with diameter of 22 ". The rear frame is also equipped with a mechanism of transfer speed in three levels. Bike length is 1645 mm, width 615 mm and height 1035 mm. However, after folded the bike dimension became 725 mm long, 460 mm wide and 1035 mm high. By using CATIA software the strength frame material is simulated and analyzed. The bike design is evaluated from ergonomics aspect with RULA method. The proposed design is performed into a prototype. The prototype test is conducted. The result test show, that the bike is pedaled, either by hand or foot, strong, safe and comfortable to ride. In order to evaluate the design benefit, the pedal test is also conducted in various pedal velocities by 3 post stroke patients as respondent. During 6 minutes pedaling number of rider heartbeat is measured. The result shows all the number of heartbeat is not exceeded than 120 HR. That means the bike is enough light to pedal or the patient must not give extra power to ride the bike. Moreover, during 4 weeks therapy by cycling the bike, pedal velocity each respondents is increase significantly around 26-96%, this means the muscle contraction of respondents is reduce and developed bike can be used as alternative equipment for physical therapy of post stroke patient. Because light and foldable, the bike can be moved easily and put in the trunk of a car without problem.

Abstract: The paper presents a stage of the research concerning the development and improvement of a low cost small flexible coordinate measuring machine (CMM) that could be used in the future both in research and industry. Its main advantage could refer to the low cost (only about 30 ÷ 40% of the cost of a CMM in the category on the market, having similar dimensions) in conditions of high performance criteria. This could be possible due to the fact that they were implemented some recycled components in the construction of the robotic drive axes of the machine structure, low cost scanning devices and low cost mechanical systems for fixing and adapting the scanning devices. The research stage presented in the paper is essential for the later stages of research to develop an integrated concept: low-cost, flexibility, precision and efficiency, all criteria referring to a small portable scanning CMM, with possible application in any domain. Specifically, the described research stage refers to evaluate the implementation of some scanning systems, type non-contact low-cost and modern displacement transducers, on the principle of emission of LASER radiation, in terms of scanning accuracy. The reason is that currently these systems are used more and more in the CMMs construction.

Abstract: After using three-dimensional software for the 2-PRR parallel mechanism modeled into ADAMS, and on one of the links in ANSYS is flexible processing of replacing the rigid rod. In ADAMS/View environment using kinematics and dynamics simulation for the 2-PRR parallel mechanism, verification of positive solution and inverse of the mechanism, and get the characteristic curves of driven torque changes of driven slider. The study concludes that parallel mechanism in engraving and milling machine tools and robots in plane design and selection provides a theoretical basis.

Abstract: In this paper, a novel monolithically integrated flexible thermal flow sensor combining four resistors in a Wheatstone bridge including hot-film resistor, temperature-compensating resistor and two other balancing resistors on one chip is proposed in order to improve the system integration level and sensor performances, such as signal to noise ratio (SNR), power consumption and temperature compensation. Fabricating the sensor directly on a flexible polyimide printed circuit board (PCB) by incorporating printed circuit technique with micromachining sputter technique is adopted. A complete performance test on the flow sensor demonstrates its superiorities on power consumption, SNR and temperature drift, the error of which is eliminated from 43% to 8% over a range of ambient temperature (35–75°C).