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Area-selective atomic layer deposition (AS-ALD) has been studied as an alternative method for metal oxide ALD film patterning in the microelectronics industry. To perform AS-ALD, area-deactivation or -activation processes should be implemented in advance using selective surface modification through a photography-based lift-off process and printing techniques. This study introduces a novel approach for Al2O3AS-ALD using inkjet-printed inhibition patterns. ALD-inhibition patterns with two-layer structures of fluorocarbon (FC) thin film and photoresist (PR) were patterned by inkjet printing. Low surface energy FC thin films were used to block the Al2O3nucleation and growth during the ALD process, and PR was patterned to easily remove ALD-inhibition patterns using a lift-off process. To demonstrate AS-ALD, an Al2O3thin film approximately 10 nm thick was deposited via an in-house built system with a multiple-slit gas source. The proposed AS-ALD method was evaluated for topological analysis using atomic force microscopy and surface composition analysis using a time of flight secondary ion mass spectrometry after Al2O3deposition and a lift-off process. Finally, a 6 nm thick Al2O3film was selectively patterned by the lift-off process using an inkjet-printed 1.28 μm thick FC-covered PR inhibition pattern.

This paper proposes the bioinspired soft frog robot. All printing technology was used for the fabrication of the robot. Polyjet printing was used to print the front and back limbs, while ultrathin filament was used to print the body of the robot, which makes it a complete soft swimming robot. Dual thrust generation approach has been proposed by embedding the main muscle and antagonistic muscle in all the limbs, which enables it to attain high speed (18 mm/s), significant control to swim in dual mode (synchronous and asynchronous modes). To achieve the swimming motion of frog, four SMA (BMF 300) muscle wires were used. The frog robot is named as (FROBOT). The hind limbs are 60 mm long and 10 mm thick on average, while the front limbs are 35 mm long and 7 mm thick. Model-based design and rigorous analysis of the dynamics of real frogs have allowed FROBOT to be developed to swim at a level that is remarkably consistent with real frogs. Electrical and mechanical characteristics have been performed. In addition, the test data were further processed using TRACKER to analyze angle, displacement and velocity. FROBOT (weighs 65 g) can swim at different controllable frequencies (0.5–2 Hz), can rotate in any direction on command from custom built LabVIEW software allowing it to swim with speed up to 18 mm/s on deep water surface (100 cm) with excellent weight balance.

Inspired by the simple yet amazing morphology of the Octopus, we propose the design, fabrication, and characterization of multi-material bio-inspired soft Octopus robot (Octobot). 3D printed molds for tentacles and head were used. The tentacles of the Octobot were casted using Ecoflex-0030 while head was fabricated using relatively flexible material, i.e., OOMOO-25. The head is attached to the functionally responsive tentacles (each tentacle is of 79.12 mm length and 7 void space diameter), whereas Shape Memory Alloy (SMA) muscle wires of 0.5 mm thickness are used in Octobot tentacles for dual thrust generation and actuation of Octobot. The tentacles were separated in two groups and were synchronously actuated. Each tentacle of the developed Octobot contains a pair of SMA muscles (SMA-α and SMA-β). SMA-α muscles being the main actuator, was powered by 9 V, 350 mA power supply, whereas SMA-β was used to provide back thrust and thus helps to increase the actuation frequency. Simulation work of the proposed model was performed in the SolidWorks environment to verify the vertical velocity using the octopus tentacle actuation. The design morphology of Octobot was optimized using simulation and TRACKER software by analyzing the experimental data of angle, displacement, and velocity of real octopus. The as-developed Octobot can swim at variable frequencies (0.5–2 Hz) with the average speed of 25 mm/s (0.5 BLS). Therefore, the proposed soft Octopus robot showed an excellent capability of mimicking the gait pattern of its natural counterpart.

Mixing of fluids flowing through channels and chambers is a crucial step in chemical and biochemical reactions inside microfluidic devices due to laminar flow because of small size channel and chamber dimensions. Mixing can be enhanced by passive or active mechanism which makes convection dominant over diffusion. To address this challenge, the study proposes three novel mixing designs: passive mixer, active mixer and a combination of active and passive mixing. These designs mixing performance has been studied by numerical simulation using COMSOL 5.3. According to the preliminary results of the study, pure active micromixer design has superior mixing ability. The mixing ability was proved by concentration line plots, concentration contours and videos. In order to further optimize the mixing index of the pure active micromixer, Taguchi method is applied against various input parametric values for micromixer such as frequency, voltage and velocity. The velocity is required for two fluids to flow, while frequency and voltages are for providing an external energy for active mixing. A total of nine cases were analyzed; the two best cases out of nine were selected for comparing mixing index line plots. The result of the study conclude that pure active micro-mixer at an optimal set of parameters, frequency of 10 Hz, velocity of 0.05 mm s–1and voltage of 0.5 V achieved 99.6% mixing index at t = 0.2 s.

This study introduces area‐selective atomic layer deposition (AS‐ALD) using fluorocarbon (FC) mask patterns with low surface energy. FC mask patterns were formed on a glass substrate by inkjet printing method. The surface energy of the printed FC thin film was 13.04 dyne/cm enough low to inhibit nucleation and growth during ALD. 10 µm wide Al2O3patterns were selectively formed by removal of FC mask patterns using oxygen plasma after Al2O3ALD processes.

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOTPSS) is an organic conductive polymer which has a great potential to replace metallic conductors in thin film electronics. This paper reports the experimental findings on the electromechanical performance of conductive PEDOTPSS thin films on a stretchable and flexible low modulus polymer substrate, polydimethylsiloxane (PDMS), having random micro-bumpy roughness features. All films were fabricated using the method of dip coating, which is cost effective and also favorable for mass production. The main goal of the study is to quantify the stretchability and bendability of dip coated PEDOTPSS thin films on PDMS substrate having random micro-bumpy type of roughness features. The films displayed almost constant resistance up to 10% axial strain and were also found to remain conductive when bent up to a diameter of 2 mm.

Titanium dioxide (TiO2) thin film was fabricated using titanium isopropoxide as a precursor through an atmospheric low-temperature roll-to-roll chemical vapor deposition method. TiO2was deposited on the PET substrate in the temperature range of room temperature to 100°C, and the working pressure was 740 Torr. The surface morphology of TiO2thin film was analyzed by field emission scanning electron microscopy and a 2D surface profiler. The results revealed that the growth rate of TiO2film was 31 nm/min at 100°C, and it also showed that the surface is uniform and smooth. Moreover, the lowest root mean square roughness (Rq) value of 1.87 nm was obtained for TiO2film prepared at 100°C. The composition of TiO2film was confirmed by X-ray photoelectron spectroscopy (XPS) analysis. The film showed very good chemical and optical properties while increasing the substrate deposition temperature. The UV–Vis spectroscopy analysis revealed that TiO2films exhibited excellent optical transmittance, more than 91% observed in the visible region.

Abstract: Electrohydrodynamic printing is a promising technique for printed electronics application. Most researchers working in this field are using a single nozzle configuration. However, for large area printing a multi-nozzle setup will be required for time and cost effective process. In this paper the influence of electric field and flow-rate on jetting angle on multi-nozzle array has been investigated experimentally. A three nozzle setup has been used in a linear array by using glass capillary as a nozzle with independent voltage applied on each nozzle and independent ink supply. The experiments are performed by changing the nozzle to nozzle gap and the effect on the jetting angle has been investigated. It has been observed that by increasing the applied voltage the jetting angle also increases at fixed flow-rate. In case of increasing the flow-rate, the jetting angle first increases with increase in flow-rate, but as the flow-rate increases at certain level the jetting angle decreases; moreover, at a high flow-rate the cone-jet length starts increasing. Numerical simulation has been performed to have a better understanding of the electric-field with respect to jetting angles. The influence of one nozzle on another nozzle is also investigated by operating the nozzle independently by using different operating cases. The cross-talk effect is also minimized by reducing the nozzle diameter. At 250 μm nozzle diameter the cross-talk effect was negligible for 5 mm nozzle-to-nozzle gap. This study will help in better understanding of the interaction between different nozzles in multi-nozzle cases and better design of the multi-nozzle system by minimizing the effects of adjacent nozzles for multi-nozzle electrohydrodynamic printing system.

Electrospray deposition is fast finding application in the field of thin film device manufacturing processes. The ease and cost efficiency attached to electrospray deposition with possible integration with roll-to-roll fabrication lines is the potential future of thin film device manufacturing. In this study thin films composed of copper-indium-diselenide, more commonly known as CIS, have been made using the electrospray deposition of nano-particle based inks for the ultimate manufacture of CIS-based solar cells. It is the first time that a complete CIS layer has been deposited through electrospray in a single step without involving any other process. Deposited layers are thoroughly characterized using techniques such as scanning electron microscope, X-ray diffraction and X-ray photoelectron spectroscopy. Moderate voltage requirements, dense, large grained, ~1 µm thick layers and reasonable sintering temperatures involved in the electrospray deposition process promise the possible applicability of electrospray deposition in the manufacturing of cheap and easy to build solar cells.

This paper analyzes and reports the influence of electrodes positioning on dielectric ink for the formation of stable meniscus in the electrostatic inkjet head, experimentally. To introduce the electrostatic inkjet head for the fabrication of different printed devices, it is important to know the best position of electrode in the inkjet head for the optimal electrification of the ink. The paper also examines electrode position and electrically driven liquid handling operations. From experiments, it has been deduced that the head performs best when the electrode position is at orifice in dielectric ink. For better understanding and evaluation of this phenomenon, simulations were also performed. The finite element model of the head with dielectric fluid has been developed to analyze the behavior under electric field. And to optimize the analysis, the research is also supported by the statistical techniques. Furthermore, the meniscus shape and response on applied voltage is studied and analyzed. Paper also elaborates and addresses issues like the meniscus generation using dielectric ink and ejections at low voltage with stability problems.

There are many applications which employed roll-to-roll web technology for mass production to make cheaper production in shorter time. Especially, RFID and printed electronics using the principle of roll-to-roll manufacturing to build equipment at high speeds will have a big impact on the printed electronics. To increase the precision and flexible ability to detect effectively the external and internal disturbance, several controller designs for roll-to-roll web control system are proposed in recent years. However, almost all proposals are employed for the time-invariant linear SISO systems. In reality, some terms in several control systems such as roll-to-roll web system change in time and are non-linear. Therefore, classical gain tuning approaches are not suitable. In this paper, an algorithm proposed for non-linear roll-to-roll web control system is based on using the modified genetic algorithm to determine the optimal parameters of controller, detect the errors and automatically recover the errors at every time interval. The simulation results in Matlab/Simulink employed firstly with the simple plants and after that with back-stepping controllers of roll-to-roll system prove the stability and reliability of the proposed approach.

Abstract: This paper represents the multiphysics simulation of droplet generation of ink containing conductive nano-particles through electrostatic forces on substrate. The main focus is to investigate the phenomena by generating the drops through a nozzle with the help of electrostatic forces. The electrostatic based deposition system has vast application in printed electronics and biotechnology. In electrostatic deposition mechanism for droplet generation, a strong electric potential is applied at the tip of the nozzle; due this electric potential, the liquid containing the nano-particles experience strong electrostatic static forces at the interface with the air (at the tip of the nozzle). When these electrostatic forces exceed the internal (viscous forces) and external forces (surface tension), a deformation takes place which results in the flow of the liquid in the form of droplets. The size of the droplet is dependent on different parameters like applied voltage, properties of the ink, dimension of the nozzle. To have better understanding of this, a numerical simulation was performed based on multi-physics approach. Multiple simulations were performed by changing the position of electrode in nozzle and varying the applied voltage. Droplet size with respect to applied voltage was evaluated; electric field with respect to applied voltage and time for the droplet generation was also evaluated through these simulations. This study will help in better understanding the parameters of droplet generation phenomena and optimal design of the nozzle for the electrostatic inkjet system.

Abstract: A solid freeform fabrication (SFF) system using selective laser sintering (SLS) is currently recognized as a leading process of fabrication using variable materials, and SLS extends the application to machinery and automobiles. Due to the time delay in the sintering process, shrinkage and warping often occur. Curling also occurs due to laser and scan delays. These problems affect not only the accuracy of the fabricated product but also the total system efficiency. These deficiencies can be overcome by reducing the total processing time of the SFF system. To accomplish this, the laser scanning time, from mark (laser on) to jump (laser off), must be reduced as it contributes the major part of the total processing time. This can be done by employing area division scan path generation, which promotes digital efficiency. A simulation and an experiment was carried out in this study to evaluate the developed scan path method.

Renal ischemic-reperfusion injury decreases the chances of long-term kidney graft survival and may lead to the loss of a transplanted kidney. During organ excision, the cycle of warm ischemia from the donor and cold ischemia is due to storage in a cold medium after revascularization following organ transplantation. The reperfusion of the kidney graft activates several pathways that generate reactive oxygen species, forming a hypoxic-reperfusion injury. Animal models are generally used to model and investigate renal hypoxic-reperfusion injury. However, these models face ethical concerns and present a lack of robustness and intraspecies genetic variations, among other limitations. We introduce a microfluidics-based renal hypoxic-reperfusion (RHR) injury-on-chip model to overcome current limitations. Primary human renal proximal tubular epithelial cells and primary human endothelial cells were cultured on the apical and basal sides of a porous membrane. Hypoxic and normoxic cell culture media were used to create the RHR injury-on-chip model. The disease model was validated by estimating various specific hypoxic biomarkers of RHR. Furthermore, retinol, ascorbic acid, and combinational doses were tested to devise a therapeutic solution for RHR. We found that combinational vitamin therapy can decrease the chances of RHR injury. The proposed RHR injury-on-chip model can serve as an alternative to animal testing for injury investigation and the identification of new therapies.

The fluidic muscle cylinder consists of an air bellows tube, flanges and lock nuts. Its features are softness of material and motion, simplicity of structure, low production cost and high power efficiency. Recently, unlike the pneumatic cylinder, the fluidic muscle cylinder without air leakage, stick slip, friction or seals was developed as a new concept actuator. It has characteristics such as light weight, low price, high response, durable design, long life, high power and high contraction. In this study, we carried out finite element modeling and analysis on the main design variables such as contraction ratio and force, and diameter increment of the fluidic muscle cylinder. On the basis of finite element analysis, the prototype fluidic muscle cylinder was fabricated and tested. Finally, we compared the test results with the finite element analysis.

In order to develop more elaborate and speedy system for large objects than existing selective laser sintering (SLS), this study applies a new selective dual-laser sintering process. It contains a 3-axis dynamic focusing scanner system for scanning large area instead of the existing fθ lens. As sintering parameters, the sintering temperature, the laser beam power and the layer thickness have a great influence on sintering of the polymer and metal powder. This paper will address the development of a solid freeform fabrication (SFF) system employing the dual laser system. Experiments were performed to evaluate the effect of a scanning path and to fabricate the large-sized object.

A new optical security system for the protection of personal identification information is proposed. First, authentication of the encrypted personal information is carried out by primary recognition of a personal identification number (PIN) with the proposed multiplexed minimum average correlation energy phase-encrypted (MMACE_p) filter. The MMACE_p filter, synthesized with phase-encrypted training images, can increase the discrimination capability and prevent the leak of personal identification information. After the PIN is recognized, speedy authentication of personal information can be achieved through one-to-one optical correlation by means of the optical wavelet filter. The possibility of information counterfeiting can be significantly decreased with the double-identification process. Simulation results demonstrate the effectiveness of the proposed technique.

It is necessary to have a dummy that describes the anthropometry of a victim with accuracy. This study presents three scaled side impact dummies constructed for the use of MADYMO. They represent five, fifty and ninety-five percentile Korean males ranged from the age of 25 through 39. Thirty-five anthropometric data were used to scale input files required for MADYSCALE. Geometries, inertia, joints and other parameters for dummies were scaled based on the configurations of EuroSID-1. This study proposes the lateral impact response requirements for head, thorax and pelvis of Korean side impact dummies. A lateral drop impact test was conducted for the head at the height of 200 mm. Lateral pendulum impact tests were also carried out for thorax and pelvis at three specific impact velocities. All these test results were obtained from simulation based on MADYMO. All the procedures of the three tests followed the requirement of ISO/TR 9790.

It is necessary to have a dummy that describes the anthropometry of a victim with accuracy. This study presents three scaled side impact dummies constructed for the use of MADYMO. They represent five, fifty and ninety-five percentile Korean males ranged from the age of 25 through 39. Thirty-five anthropometric data were used to scale input files required for MADYSCALE. Geometries, inertia, joints and other parameters for dummies were scaled based on the configurations of EuroSID-1. This study proposes the lateral impact response requirements for head, thorax and pelvis of Korean side impact dummies. A lateral drop impact test was conducted for the head at the height of 200 mm. Lateral pendulum impact tests were also carried out for thorax and pelvis at three specific impact velocities. All these test results were obtained from simulation based on MADYMO. All the procedures of the three tests followed the requirement of ISO/TR 9790.

A shop floor can be considered an important level at which to develop computer integrated manufacturing systems (CIMs). The shop floor is a dynamic environment where unexpected events continuously occur, and it imposes changes to planned activities. The shop floor should adopt an appropriate control system that is responsible for scheduling coordination and moving manufacturing material and information flow. In this paper, an architecture of a hybrid control model identifies three levels: I.e. a shop floor controller (SFC), a cell controller (CC) and an equipment controller (EC). The methodology for developing these controllers is to employ an object-oriented approach for static models, IDEF0 for function models for dispatching a job. A new methodology, called the Multi-Layered Operation Model (MuLOM), will represent various activities, and control logic involved in the shop floor will be introduced and tested with an illustration of a simple hypothetical cell and equipment. SFC and CC are coordinated, employing multi-factor bidding, and an adapted Analytic Hierarchy Process (AHP) proves the applicability of the suggested method. Test experiments have been conducted on the shop floor, which consisted of six manufacturing cells.

Abstract: A shop floor can be considered as an important level to develop Computer Integrated Manufacturing system (CIMs). However, a shop floor is a dynamic environment where unexpected events continuously occur, and impose changes to the planned activities. To deal with this problem, a shop floor should adopt an appropriate control system that is responsible for the coordination and control of the manufacturing physical flow and information flow. In this paper, a hybrid control system is described with a shop floor activity methodology called Multi-Layered Task Initiation Diagram (MTD). The architecture of the control model contains three levels: i.e., the shop floor controller (SFC), the intelligent agent controller (IAC) and the equipment controller (EC). The methodology behind the development of the control system is an intelligent multi-agent paradigm that enables the shop floor control system to be an independent, an autonomous, and distributed system, and to achieve an adaptability to change of the manufacturing environment.

Abstract: The primary goal of virtual prototyping is to eliminate the need for fabricating physical prototypes, and to reduce cost and time for developing new products. A virtual prototyping seeks to create a virtual environment where the development of a new model can be flexible as well as rapid, and experiments can be carried out effectively concerning kinematics, dynamics, and control aspects of the model. This paper addresses the virtual environment used for virtual prototyping of a passenger vehicle. It has been developed using the dVISE environment model including features, functions, and behaviors is constructed by employing an object-oriented paradigm and contains detailed information about a real-size vehicle. The human model is also implemented not only for visual and reach evaluations of the developed vehicle model, but also for behavioral visualization during a crash test. For the real time driving simulation, a neural network model is incorporated into the virtual environment. The cases of passing bumps with a vehicle are discussed in order to demonstrate the applicability of a set of developed models.

A Flexible manufacturing Cells (FMC) considered as a best production tool for Computer-Integrated Manufacturing (CIM) usually consists of a number of NC machines, sensor systems for the cell monitoring, robots for all par loading and unloading, and a cell controller. Most of the machines comprising an FMC are typically from different machine tool manufacturers with different communication hardware standards, protocols, and control languages. These problems lead to difficulties in integrating cell constituents and employing FMCs in a real manufacturing environment. In this study a cell controller is being developed to deal with above problems. It is designed based upon object-oriented principles, and has tow major modules: configuration and multi-layered control. Since the cell controller developed is independent of specific machine tool requirement, it allows not only operators to choose suitable machine tools for their manufacturing systems but also the machine tools innovation.

This paper describes a cost-based algorithm that deals with the design problems of Cellular Manufacturing Systems (CMS) associated exceptional parts and bottleneck machines. The developed algorithm employes explicitly the main elements of manufacturing costs, such as the fixed machine cost, the production cost, the setup cost, and the material handling cost. The algorithm is based on the minimization of sum of these costs, and considers three alternatives to solve exceptional issues. The first alternative is to try to eliminate the maximum number of intercellular movements from the presently configured manufacturing system by buying and installing extra bottleneck machines into the appropriate cells. The second alternative considers the alternative process plans available and tries to complete the job using the overtime basis in the small machine cells. The third alternative considers the possibility of subcontracting the processing operations of exceptional part(s) to outside vendors to reduce the overall cost for the manufacturing system. The total costs of the three cases are compared and the best alternative for any given problem is identified. In order to illustrate performance of the algorithm developed, a test example is provided.

A multilayer separator is developed by the deposition of ultrathin polyvinylidene fluoride (PVDF) and aluminum oxide (Al2O3) layers on polyolefin separator using in-house designed novel roll-to-roll atmospheric atomic layer deposition (R2R-AALD) and electrohydrodynamic atomization (EHDA) methods. The conformal coatings of ultrathin PVDF (?5 um) and Al2O3(?10 nm) layers form a highly uniform interconnect microporous structure, which enhances thermal stability and mechanical strength. The deposition of PVDF and Al2O3layers also improves electrolyte wettability and electrolyte uptake (256%), which gives rise to ionic conductivity. The Al2O3/PVDF/Celgard separator shows excellent thermal stability with minimal shrinkage up to 180 °C and robust mechanical strength. The lithium cobalt oxide/graphite (LCO/graphite) cells based on as-developed multilayer separator deliver excellent discharge capacity of 130.9 mAh g?1at 0.5 C after 150 cycles and capability of 99.6 mAh g?1at 5 C after 100 cycles at room temperature. Moreover, the LCO/graphite cells with Al2O3/PVDF/Celgard separator also show remarkable cyclic performances at elevated temperatures. The as-developed separator proves to be a better candidate for high capacity lithium ion batteries, especially for high temperature conditions.

Poly[2-methoxy-5-(2$'$-ethylhexyloxy)--($p$-phenylenevinylene)] (MEH:PPV) based organic memristor (memory resistor) has been fabricated on the indium--tin oxide (ITO) coated poly(ethylene terepthalate) (PET) substrate by the electrohydrodynamic atomization (EHDA) technique. Thin jet containing MEH:PPV polymer was generated through a capillary under electrical stresses. The jet was broken into small droplets by adjusting the distance from nozzle to substrate and collected over the substrate under normal room conditions, consequently a high quality layer of MEH:PPV was achieved with an average thickness of 168 nm. The layer was morphologically characterized by a field emission scanning electron microscope (FESEM) analysis. X-ray photoelectron spectroscope (XPS) analysis was also carried out to confirm the chemistry of the deposited material. Electrically, ITO/MEH:PPV/Ag fabricated memristor was found to be switchable between high state and low state between $\pm 4$ V. The research work provides the memristive behavior in electrohydrodynamic atomized layers of MEH:PPV to be used for the next generation printed electronics application.

This paper presents the electrospray deposition of solution-based ZnO nanoparticles. Transparent thin film transistors in active matrix displays have become the most interested research area. Electrospray assures direct deposition by eliminating etching steps required after deposition by other techniques. Uniform layers of minimum thickness 87 nm on glass and 356 nm on polyimide using electrospray experiment is achieved. Contact angle analyzer has been used for finding properties like wetting energy, spreading coefficient and work of adhesion of the ink on glass and polyimide substrates. All experiments were performed in ambient conditions.