Name: study of a dot-patterning process on flexible materials using impact print-type hot embossing technology
Uploaded: 2020-04-06T14:00:00
Description: Watch this Scientific Journal Video about Study of a Dot-patterning Process on Flexible Materials using Impact Print-Type Hot Embossing Technology at JoVE.com

This research is supported by the project entitled "Development of impact print-type hot embossing technology for a conductive layer using conductive nano-composite materials" through the Ministry of Trade, Industry and Energy (MOTIE) of Korea (N046100024, 2016).

1. Fabrication of the impact print-type hot embossing process
<ol>
	<li>Make model 1 and combine it with an X-stage (see Figure 1). 
	NOTE: It is recommended that Model 1 be made of aluminum to avoid heat being conducted onto the X-stage. Moreover, it is recommended that the length of Model 1 be the distance between the surface of the heat plate and the lowest height of the bearing plate of the Z-stage as the design of Model 1 varies with the size of the heat plate.</li>
	<li>Combine ...

<ol>
	<li>Lee, S. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=2018+Optical+Fiber+Communications+Conference+and+Exposition+(OFC).">2018 Optical Fiber Communications Conference and Exposition (OFC).</a> IEEE. , 1-3 (2019).</li><li>Yang, D., Pan, L., Mu, T., Zhou, X., Zheng, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+fabrication+of+electrochemical+geophone+based+on+FPCB+process+technology.">The fabrication of electrochemical geophone based on FPCB process technology.</a> Journal of Measurements in Engineering. 5 (4), 235-239 (2017).</li><li>Fukuda, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fully+printed+high-performance+organic+thin-film+transistors+and+circuitry+on+one-micron-thick+polymer+films.">Fully printed high-performance organic thin-film transistors and circuitry on one-micron-thick polymer films.</a> Nature Communications. 5, 4147 (2014).</li><li>Sekitani, T., Zschieschang, U., Klauk, H., Someya, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flexible+organic+transistors+and+circuits+with+extreme+bending+stability.">Flexible organic transistors and circuits with extreme bending stability.</a> Nature Materials. 9 (12), 1015 (2010).</li><li>Zamkotsian, F., Dohlen, K., Burgarella, D., Ferrari, M., Buat, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=International+Conference+on+Space+Optics-ICSO+2000.">International Conference on Space Optics-ICSO 2000.</a> International Society for Optics and Photonics. , 105692A (2019).</li><li>Zhang, X., Li, Z., Zhang, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+performance+ultra-precision+turning+of+large-aspect-ratio+rectangular+freeform+optics.">High performance ultra-precision turning of large-aspect-ratio rectangular freeform optics.</a> CIRP Annals. 67 (1), 543-546 (2018).</li><li>Ziaie, B., Baldi, A., Lei, M., Gu, Y., Siegel, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hard+and+soft+micromachining+for+BioMEMS:+review+of+techniques+and+examples+of+applications+in+microfluidics+and+drug+delivery.">Hard and soft micromachining for BioMEMS: review of techniques and examples of applications in microfluidics and drug delivery.</a> Advanced Drug Delivery Reviews. 56 (2), 145-172 (2004).</li><li>Mishra, S., Yadava, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+beam+micromachining+(LBMM)-a+review.">Laser beam micromachining (LBMM)-a review.</a> Optics and Lasers in Engineering. 73, 89-122 (2015).</li><li>Yun, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+roll-to-roll+hot+embossing+system+with+induction+heater+for+micro+fabrication.">Development of roll-to-roll hot embossing system with induction heater for micro fabrication.</a> Review of Scientific Instruments. 83 (1), 015108 (2012).</li><li>Ker&#228;nen, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Roll-to-roll+printed+and+assembled+large+area+LED+lighting+element.">Roll-to-roll printed and assembled large area LED lighting element.</a> The International Journal of Advanced Manufacturing Technology. 81 (1-4), 529-536 (2015).</li><li>Park, J., Lee, J., Park, S., Shin, K. H., Lee, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+hybrid+process+for+double-side+flexible+printed+circuit+boards+using+roll-to-roll+gravure+printing,+via-hole+printing,+and+electroless+plating.">Development of hybrid process for double-side flexible printed circuit boards using roll-to-roll gravure printing, via-hole printing, and electroless plating.</a> The International Journal of Advanced Manufacturing Technology. 82 (9-12), 1921-1931 (2016).</li><li>Rank, A., Lang, V., Lasagni, A. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-Speed+Roll-to-Roll+Hot+Embossing+of+Micrometer+and+Sub+Micrometer+Structures+Using+Seamless+Direct+Laser+Interference+Patterning+Treated+Sleeves.">High-Speed Roll-to-Roll Hot Embossing of Micrometer and Sub Micrometer Structures Using Seamless Direct Laser Interference Patterning Treated Sleeves.</a> Advanced Engineering Materials. 19 (11), 1700201 (2017).</li><li>Shan, X., Liu, T., Mohaime, M., Salam, B., Liu, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large+format+cylindrical+lens+films+formed+by+roll-to-roll+ultraviolet+embossing+and+applications+as+diffusion+films.">Large format cylindrical lens films formed by roll-to-roll ultraviolet embossing and applications as diffusion films.</a> Journal of Micromechanics and Microengineering. 25 (3), 035029 (2015).</li><li>Wang, X., Liedert, C., Liedert, R., Papautsky, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+disposable,+roll-to-roll+hot-embossed+inertial+microfluidic+device+for+size-based+sorting+of+microbeads+and+cells.">A disposable, roll-to-roll hot-embossed inertial microfluidic device for size-based sorting of microbeads and cells.</a> Lab on a Chip. 16 (10), 1821-1830 (2016).</li><li>Yun, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+Print-Type+Hot+Embossing+Process+Technology.">Impact Print-Type Hot Embossing Process Technology.</a> Advanced Engineering Materials. 20 (9), 1800386 (2018).</li><li>Ahn, J., Yun, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analyzing+Electromagnetic+Actuator+based+on+Force+Analysis.">Analyzing Electromagnetic Actuator based on Force Analysis.</a> 2019 IEEE International Conference on Robotics and Automation (ICRA). , (2019).</li></ol>

In this study, we implemented the impact print-type hot embossing process and engraved dot patterns with various widths and depths onto a range of polymer films in real time. Among the protocol steps, two steps should be critically considered among all steps. The first is the setting of the temperature of the heat plate (step 3.3.3), and the second is the setting of the initial position of the impact header (step 3.5.1). In step 3.3.3, if the temperature of the heat plate is too high, it becomes difficult to form a patte...

Researchers are actively attempting to miniaturize existing devices and displays and increase the flexibility of these devices1,2. To reduce the width and depth of electrical channels to the micro or nano scale, high-precision technology is necessary. In addition, to increase the flexibility of these devices, the patterns of the electrical channels must be located on a flexible material, such as a polymer film3,4. To meet these conditions, the study of ultrafine microprocessing technology is actively underway.
Ultrafine microfabrication technology has an advantage in that possible patterning materials include not only highly rigid materials such as iron or plastic but also soft materials such as polymer films. Due to these advantages, this technology is widely used as a core process in various fields, such as communications, chemistry, optics, aerospace, semiconductor, and sensors5,6,7. In the ultrafine microprocessing field, LIGA (lithography, electroplating, and molding) or micromachining methods are used8. However, these conventional methods are associated with several problems. LIGA methods require a considerable amount of time and several process steps to create ultrafine patterns and incur a high cost as well because they need many different types of equipment during the processes. In addition, LIGA methods use chemicals that can pollute the environment.
To address this issue, hot embossing process technology has been spotlighted among ultrafine microprocess technologies. Hot embossing is a technology that creates a pattern on a heated polymer film using a micro- or nanoscale embossing mold. Conventional hot embossing technology is divided into the plate type and roll-to-roll type depending on the shape of the mold. The two types of hot embossing technology are different in terms of the shape of the mold, but these two processes are similar in that the embossing mold presses the polymer film onto a heated plate to engrave a pattern onto the polymer film. To engrave the pattern using the hot embossing process, it is necessary to heat the polymer film above the glass transition temperature and to apply an adequate amount of pressure (~30&#8211;50 MPa)9. In addition, the width and depth of the pattern change depending on the temperature of the heated plate, the material, and the shape of the embossing mold. Moreover, the cooling method after the patterning process affects the shape of the pattern on the polymer film.
In the conventional hot embossing process, embossing stamps or rollers can be embossed with the desired pattern, and the embossing mold can be used to print the same pattern onto polymer film surfaces continuously. This feature makes this process suitable not only for mass production but also for fabricating devices with soft materials, such as polymer films10,11,12,13,14. However, the conventional hot embossing method can only create the single pattern engraved in the embossing mold. Therefore, when the user wants to make a new pattern or modify the pattern, they must make a new mold to modify the imprinting pattern. For this reason, conventional hot embossing is costly and time-consuming when creating new patterns or replacing existing designs.
Earlier work introduced the impact-type hot embossing process for producing dot patterns with various widths and depths in real time15. Unlike the conventional hot embossing process, the impact print-type hot embossing method uses an impact header to create patterns on the polymer film. This technology moves the impact header to the desired position with a precision positioning system. A control signal is applied to print patterns at a desired width and depth and at an arbitrary position. The structure of the impact header consists of a mover, a spring, a coil winding, and a core (see Figure 1A)15. Earlier work confirmed through an analysis and experiment that such an impact header can produce the proper force for hot embossing16. The protocol of this paper covers the design of the hardware for the impact-type hot embossing process and the control environment for process control. In addition, we analyze the dot patterns on PET film, PMMA film, and PVC film, all of which are processed with the proposed protocol to verify that the impact print-type hot embossing process can create dot patterns with various widths and depths in real time. The results of these experiments are presented below in the results section, confirming that the embossing process can suitably produce ultrafine patterns.

<table>
	<tbody>
		<tr>
			<td>0.3mm High Quality Clear Rigid Packaging PVC Film Roll For Vacuum Forming</td>
			<td>Sunyo</td>
			<td>SY1023</td>
			<td>PVC film / Thickness : 300&#181;m</td>
		</tr>
		<tr>
			<td>Acryl(PMMA) film</td>
			<td>SEJIN TS</td>
			<td>C200</td>
			<td>PMMA film / Thickness : 175&#181;m</td>
		</tr>
		<tr>
			<td>Confocal Laser Scanning Microscope: 3D-Topography for Materials Analysis and Testing</td>
			<td>Carl Zeiss</td>
			<td>LSM 700</td>
			<td>3D confocal microscope / Supporting Mode : 2D, 2.5D, 3D topography</td>
		</tr>
		<tr>
			<td>DAQ board</td>
			<td>NATIONAL INSTRUMENTS</td>
			<td>USB-6211</td>
			<td>Control board for two stage and impact header / 16 inputs, 16-bit, 250kS/s, Multifunction I/O</td>
		</tr>
		<tr>
			<td>DC Power Supply</td>
			<td>SMART</td>
			<td>RDP-305AU</td>
			<td>3 channel power supply / output voltage : 0~30V, Output current : 0~5A</td>
		</tr>
		<tr>
			<td>L511 stage</td>
			<td>PI</td>
			<td>L511.20SD00</td>
			<td>Z-stage / Travel range : 52mm</td>
		</tr>
		<tr>
			<td>Large Digital Hotplate</td>
			<td>DAIHAN Scientific</td>
			<td>HPLP-C-P</td>
			<td>Heatplate / Max Temp : 350&#186;C</td>
		</tr>
		<tr>
			<td>M531 stage</td>
			<td>PI</td>
			<td>M531.2S1</td>
			<td>X-stage / Travel range : 306mm</td>
		</tr>
		<tr>
			<td>Mylar Polyester PET films</td>
			<td>CSHyde</td>
			<td>48-2F-36</td>
			<td>PET film / Thickness : 50&#181;m</td>
		</tr>
		<tr>
			<td>OPA2541</td>
			<td>BURR-BROWN</td>
			<td>OPA2541BM</td>
			<td>OP-AMP / Output currents : 5A, output voltage : &#177;40V</td>
		</tr>
	</tbody>
</table>

study of a dot-patterning process on flexible materials using impact print-type hot embossing technology

Here we present our study on an impact print-type hot embossing process which can create dot patterns with various designs, widths, and depths in real time on polymer film. In addition, we implemented a control system for the on-off motion and position of the impact header to engrave different dot patterns. We performed dot patterning on various polymer films, such as polyester (PET) film, polymethyl methacrylate (PMMA) film, and polyvinyl chloride (PVC) film. The dot patterns were measured using a confocal microscope, and we confirmed that the impact print-type hot embossing process produces fewer errors during the dot patterning process. As a result, the impact print-type hot embossing process is found to be suitable for engraving dot patterns on different types of polymer films. In addition, unlike the conventional hot embossing process, this process does not use an embossing stamp. Therefore, the process is simple and can create dot patterns in real time, presenting unique advantages for mass production and small-quantity batch production.

The impact print-type hot embossing process is a process that can be used to engrave dot patterns onto a polymer film in real time, as shown in Figure 1. This process can resolve the issues of the high cost and long times for pattern replacement associated with the existing hot embossing process. A control circuit was constructed, as shown in Figure 2 (see steps 2.3&#8211;2.3.9), using the DAQ, OP-AMP, and power supply to carve patterns on various types of polym...

Watch this Scientific Journal Video about Study of a Dot-patterning Process on Flexible Materials using Impact Print-Type Hot Embossing Technology at JoVE.com

Study of a Dot-patterning Process on Flexible Materials using Impact Print-Type Hot Embossing Technology

Impact print-type hot embossing technology uses an impact header to engrave dot patterns on flexible materials in real time. This technology has a control system for controlling the on-off motion and position of the impact header to create dot patterns with various widths and depths on different polymer films.

Here we present our study on an impact print-type hot embossing process which can create dot patterns with various designs, widths, and depths in real ...

Impact Print-Type Hot Embossed technology can make dot patterns that can change pattern width and depth in real time, on various types of polymer films, using an impact pattern. Compared to the existing hot embossing technology, the cost of the pressed pattern shape is significantly lower and arbitrary embossing shape can be made in real time. Our technology can be applied to the bio devices field and these devices can help to check the patient condition or disease by reading the biosignals of the user.If the electricity heat is too low, the impact header can tear the polymer film or the impact head may wear down. Therefore, finding a proper electricity heat from repetitive experiments is important. Begin by making model one and combine it with an X stage.Combine the X stage and Z stage, and assemble the Z stage and model two. Next, combine model two and the impact header, and place the heat plate below model one. Install two film holders onto the end of the heat plate, and fix the polymer film onto the film holder.Then, to ensure that the polymer film is flat on the heat plate, pull the polymer film as much as possible using motion one of the film holder. Alternatively, to move the polymer film to the side, move the film holder via motion two. Finally, connect the control device that sends the signals to the impact header to control it, and input minus 3v and plus 10v as control signals into the impact header.Finally, connect the control device that sends the signals to the impact header to control it, and input minus 3 volts and plus 10 volts as control signals into the impact header. Begin by installing a stage control program on the control PC to control the X stage and Z stage. Install DAQ driver software to detect the control device on the control PC that controls the impact header, and install an operating program to control the control device.Next, to conduct the patterning experiment, fix the polymer film onto the film holder, and adjust the position of the polymer film using motions one and two, to fix the film flatly. After fixing the polymer film, adjust the temperature of the heat plate to heat the film above the glass transition temperature. Then, adjust the initial position of the impact header by controlling the X and Z stages using the stage control program.Use the operating program to generate a 5v control signal from the control device. Once the OP amp amplifies the 5v control signal to greater than 10v, turn the impact header on and engrave the patterns on the polymer film. Then, generate a 0v control signal from the control device using the operating program.Once the OP amp amplifies the 0v control signal to minus 3v, turn the impact header off. Move the X stage into position to engrave the next pattern. Lower the Z stage ten microns from the initial position and engrave patterns three times on the polymer film, counting the number of Z stage moves.When the number of Z stage movements exceeds three, move the X stage to the initial position, and raise the impact header maximally by moving the Z stage. Finally, detach the polymer film from the film holder and measure the width and depth of each dot pattern using a confocal microscope in laser scanning mode. In this study, a dot pattern was created on the three polymer films, and a confocal microscope was used to observe the pattern.Nine points were used in the dot pattern, and the size of the pattern increased from sample one to sample three because the height of the Z stage moved down by ten microns. Further, this protocol was able to measure the pattern width and depth of each dot pattern, and the pattern was clearly observable through the 2D image of one dot. The errors in the dot patterns for the three types of films are minor, indicating that the Impact Print-Type Hot Embossing process is suitable for engraving micro-patterns onto polymer films in real time.This method is the first of proposed methods, so it will be a help for beginners to understand the acumen design, specimen preparation, and process procedure by visualization. In this step, if the film is heated at rest at the glass transition temperature, the pattern will not engrave there, due to the restoration of the film. Documentation of the patterning temperature is 350 degrees celsius and our process can adjust to the line patterning.These advantages can be used in the semiconductor, using high temperatures and ultra-fine channels. Our technology can make a pattern using contour systems. This protocol helps open the way for research that can make micro-scale patterns at low-cost, without chemical process.There is no risk of chemical tears, however during the experiment the user has to use protective equipment to avoid burns, since the heat plate is heated to high temperatures.

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Engineering

Micro 3D Printing Using a Digital Projector and its Application in the Study of Soft Materials Mechanics

Buckling is a classical topic in mechanics. While buckling has long been studied as one of the major structural failure modes1, it has recently drawn new attention as a unique mechanism for pattern transformation. Nature is full of such examples where a wealth of exotic patterns are formed through mechanical instability2-5. Inspired by this elegant mechanism, many studies have demonstrated creation and transformation of patterns using soft materials such as elastomers and hydrogels6-11. Swelling gels are of particular interest because they can spontaneously trigger mechanical instability to create various patterns without the need of external force6-10. Recently, we have reported demonstration of full control over buckling pattern of micro-scaled tubular gels using projection micro-stereolithography (P&mu;SL), a three-dimensional (3D) manufacturing technology capable of rapidly converting computer generated 3D models into physical objects at high resolution12,13. Here we present a simple method to build up a simplified P&mu;SL system using a commercially available digital data projector to study swelling-induced buckling instability for controlled pattern transformation.
A simple desktop 3D printer is built using an off-the-shelf digital data projector and simple optical components such as a convex lens and a mirror14. Cross-sectional images extracted from a 3D solid model is projected on the photosensitive resin surface in sequence, polymerizing liquid resin into a desired 3D solid structure in a layer-by-layer fashion. Even with this simple configuration and easy process, arbitrary 3D objects can be readily fabricated with sub-100 &mu;m resolution.
This desktop 3D printer holds potential in the study of soft material mechanics by offering a great opportunity to explore various 3D geometries. We use this system to fabricate tubular shaped hydrogel structure with different dimensions. Fixed on the bottom to the substrate, the tubular gel develops inhomogeneous stress during swelling, which gives rise to buckling instability. Various wavy patterns appear along the circumference of the tube when the gel structures undergo buckling. Experiment shows that circumferential buckling of desired mode can be created in a controlled manner. Pattern transformation of three-dimensionally structured tubular gels has significant implication not only in mechanics and material science, but also in many other emerging fields such as tunable matamaterials.

We demonstrate controlled pattern transformation of swelling gel tubes by elastic instability. A simple projection micro stereo-lithography setup is built using an off-the-shelf digital data projector to fabricate three-dimensional polymeric structures in a layer-by-layer fashion. Swelling hydrogel tubes under mechanical constraint display various circumferential buckling modes depending on dimension.

Buckling is a classical topic in mechanics. While buckling has long been studied as one of the major structural failure modes1, it has recently drawn new ...

Fast Imaging Technique to Study Drop Impact Dynamics of Non-Newtonian Fluids

In the field of fluid mechanics, many dynamical processes not only occur over a very short time interval but also require high spatial resolution for detailed observation, scenarios that make it challenging to observe with conventional imaging systems. One of these is the drop impact of liquids, which usually happens within one tenth of millisecond. To tackle this challenge, a fast imaging technique is introduced that combines a high-speed camera (capable of up to one million frames per second) with a macro lens with long working distance to bring the spatial resolution of the image down to 10 &#181;m/pixel. The imaging technique enables precise measurement of relevant fluid dynamic quantities, such as the flow field, the spreading distance and the splashing speed, from analysis of the recorded video. To demonstrate the capabilities of this visualization system, the impact dynamics when droplets of non-Newtonian fluids impinge on a flat hard surface are characterized. Two situations are considered: for oxidized liquid metal droplets we focus on the spreading behavior, and for densely packed suspensions we determine the onset of splashing. More generally, the combination of high temporal and spatial imaging resolution introduced here offers advantages for studying fast dynamics across a wide range of microscale phenomena.

Drop impact of non-Newtonian fluids is a complex process since different physical parameters influence the dynamics over a very short time (less than one tenth of a millisecond). A fast imaging technique is introduced in order to characterize the impact behaviors of different non-Newtonian fluids.

In the field of fluid mechanics, many dynamical processes not only occur over a very short time interval but also require high spatial resolution for ...

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film synthesis) for the purpose of exploratory materials research. Certain materials pose a challenge wherein the traditional bulk Hall bar device fabrication method is insufficient to produce a measureable device for sample transport measurement, principally because the single crystal size is too small to attach wire leads to the sample in a Hall bar configuration. This can be, for example, because the first batch of a new material synthesized yields very small single crystals or because flakes of samples of one to very few monolayers are desired. In order to enable rapid characterization of materials that may be carried out in parallel with improvements to their growth methodology, a method of device fabrication for very small samples has been devised to permit the characterization of novel materials as soon as a preliminary batch has been produced. A slight variation of this methodology is applicable to producing devices using exfoliated samples of two-dimensional materials such as graphene, hexagonal boron nitride (hBN), and transition metal dichalcogenides (TMDs), as well as multilayer heterostructures of such materials. Here we present detailed protocols for the experimental device fabrication of fragments and flakes of novel materials with micron-sized dimensions onto substrate and subsequent measurement in a commercial superconducting magnet, dry helium close-cycle cryostat magnetotransport system at temperatures down to 0.300 K and magnetic fields up to 12 T.

We describe the methodology of mechanical exfoliation and deposition of flakes of novel materials with micron-sized dimensions onto substrate, fabrication of experimental device structures for transport experimentation, and the magnetotransport measurement in a dry helium close-cycle cryostat at temperatures down to 0.300 K and magnetic fields up to 12 T.

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film ...

Adsorption Device Based on a Langatate Crystal Microbalance for High Temperature High Pressure Gas Adsorption in Zeolite H-ZSM-5

We present a high-temperature and high-pressure gas adsorption measurement device based on a high-frequency oscillating microbalance (5 MHz langatate crystal microbalance, LCM) and its use for gas adsorption measurements in zeolite H-ZSM-5. Prior to the adsorption measurements, zeolite H-ZSM-5 crystals were synthesized on the gold electrode in the center of the LCM, without covering the connection points of the gold electrodes to the oscillator, by the steam-assisted crystallization (SAC) method, so that the zeolite crystals remain attached to the oscillating microbalance while keeping good electroconductivity of the LCM during the adsorption measurements. Compared to a conventional quartz crystal microbalance (QCM) which is limited to temperatures below 80 &#176;C, the LCM can realize the adsorption measurements in principle at temperatures as high as 200-300 &#176;C (i.e., at or close to the reaction temperature of the target application of one-stage DME synthesis from the synthesis gas), owing to the absence of crystalline-phase transitions up to its melting point (1,470 &#176;C). The system was applied to investigate the adsorption of CO2, H2O, methanol and dimethyl ether (DME), each in the gas phase, on zeolite H-ZSM-5 in the temperature and pressure range of 50-150 &#176;C and 0-18 bar, respectively. The results showed that the adsorption isotherms of these gases in H-ZSM-5 can be well fitted by Langmuir-type adsorption isotherms. Furthermore, the determined adsorption parameters, i.e., adsorption capacities, adsorption enthalpies, and adsorption entropies, compare well to literature data. In this work, the results for CO2 are shown as an example.

A protocol for high-temperature and high-pressure gas adsorption measurements on zeolite H-ZSM-5 using an adsorption measurement device based on a langatate crystal microbalance is presented. Prior to the adsorption measurements, the synthesis of zeolite H-ZSM-5 on the langatate crystal microbalance sensor by the steam-assisted crystallization (SAC) method is demonstrated.

We present a high-temperature and high-pressure gas adsorption measurement device based on a high-frequency oscillating microbalance (5 MHz langatate ...

Challenges in Rheological Characterization of Highly Concentrated Suspensions &#8212; A Case Study for Screen-printing Silver Pastes

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the manifold requirements during processing and application of such complex fluids. In this investigation, measuring protocols for a conclusive assessment of different process relevant rheological parameters have been evaluated. This includes the determination of yield stress, viscosity, wall slip velocity, structural recovery after large deformation and elongation at break as well as tensile force during filament stretching.
The importance of concomitant video recordings during parallel-plate rotational rheometry for a significant determination of rheological quantities is demonstrated. The deformation profile and flow field at the sample edge can be determined using appropriate markers. Thus, measurement parameter settings and plate roughness values can be identified for which yield stress and viscosity measurements are possible. Slip velocity can be measured directly and measuring conditions at which plug flow, shear banding or sample spillover occur can be identified clearly. 
Video recordings further confirm that the change in shear moduli observed during three stage oscillatory shear tests with small deformation amplitude in stage I and III but large oscillation amplitude in stage II can be directly attributed to structural break down and recovery. For the pastes investigated here, the degree of irreversible, shear-induced structural change increases with increasing deformation amplitude in stage II until a saturation is reached at deformations corresponding to the crossover of G' and G'', but the irreversible damage is independent of the duration of large amplitude shear. 
A capillary breakup elongational rheometer and a tensile tester have been used to characterize deformation and breakup behavior of highly filled pastes in uniaxial elongation. Significant differences were observed in all experiments described above for two commercial screen-printing silver pastes used for front side metallization of Si-solar cells.

Challenges in Rheological Characterization of Highly Concentrated Suspensions &amp;#8212; A Case Study for Screen-printing Silver Pastes

A protocol for a robust and application relevant rheological characterization of highly concentrated suspensions is presented. Silver pastes used for screen-printing application in solar cell production are employed as model systems.

A comprehensive rheological characterization of highly concentrated suspensions or pastes is mandatory for a targeted product development meeting the ...

Predicting Catalyst Extrudate Breakage Based on the Modulus of Rupture

The mechanical strength of extruded catalysts and their natural or forced breakage by either collision against a surface or by a compressive load in a fixed bed are important phenomena in catalyst technology. The mechanical strength of the catalyst is measured here by its bending strength or flexural strength. This technique is relatively new from the perspective of applying it to commercial catalysts of typical sizes used in the industry. Catalyst breakage by collision against a surface is measured after a fall of the extrudates through the ambient air in a vertical pipe. Quantifying the impact force is done theoretically by applying Newton's second law. Measurement of catalyst breakage due to stress in a fixed bed is done following the standard procedure of the bulk crush strength test. Novel here is the focus on measuring the reduction in the length to diameter ratio of the extrudates as a function of the stress.

Here we present a protocol to measure the modulus of rupture of an extruded catalyst and the breakage of said catalyst extrudates by collision against a surface or by compression in a fixed bed.

The mechanical strength of extruded catalysts and their natural or forced breakage by either collision against a surface or by a compressive load in a ...

A Fabrication and Measurement Method for a Flexible Ferroelectric Element Based on Van Der Waals Heteroepitaxy

Flexible non-volatile memories have received much attention as they are applicable for portable smart electronic device in the future, relying on high-density data storage and low-power consumption capabilities. However, the high-quality oxide based nonvolatile memory on flexible substrates is often constrained by the material characteristics and the inevitable high-temperature fabrication process. In this paper, a protocol is proposed to directly grow an epitaxial yet flexible lead zirconium titanate memory element on muscovite mica. The versatile deposition technique and measurement method enable the fabrication of flexible yet single-crystalline non-volatile memory elements necessary for the next generation of smart devices.

In this paper, we present a protocol to directly grow an epitaxial yet flexible lead zirconium titanate memory element on muscovite mica.

Flexible non-volatile memories have received much attention as they are applicable for portable smart electronic device in the future, relying on ...

Fabrication of Flexible Image Sensor Based on Lateral NIPIN Phototransistors

Flexible photodetectors have been intensely studied for the use of curved image sensors, which are a crucial component in bio-inspired imaging systems, but several challenging points remain, such as a low absorption efficiency due to a thin active layer and low flexibility. We present an advanced method to fabricate a flexible phototransistor array with an improved electrical performance. The outstanding electrical performance is driven by a low dark current owing to deep impurity doping. Stretchable and flexible metal interconnectors simultaneously offer electrical and mechanical stabilities in a highly deformed state. The protocol explicitly describes the fabrication process of the phototransistor using a thin silicon membrane. By measuring I-V characteristics of the completed device in deformed states, we demonstrate that this approach improves the mechanical and electrical stabilities of the phototransistor array. We expect that this approach to a flexible phototransistor can be widely used for the applications of not only next-generation imaging systems/optoelectronics but also wearable devices such as tactile/pressure/temperature sensors and health monitors.

We present a detailed method to fabricate a deformable lateral NIPIN phototransistor array for curved image sensors. The phototransistor array with an open mesh form, which is composed of thin silicon islands and stretchable metal interconnectors, provides flexibility and stretchability. The parameter analyzer characterizes the electrical property of the fabricated phototransistor.

Flexible photodetectors have been intensely studied for the use of curved image sensors, which are a crucial component in bio-inspired imaging systems, ...

Data Communication Based on MQTT in a Polymer Extrusion Process

This work aims at building a flexible data communication structure for a polymer processing machine by employing a publisher-subscriber based protocol called Message Queuing Telemetry Transport (MQTT), which is operated over TCP/IP. Even when using conventional equipment, processing data can be measured and recorded by various devices anywhere through an Internet communication. A message-based protocol allows flexible communication that overcomes the shortcomings of the existing server-client protocol. Multiple devices can subscribe to the processing data published by source devices. The proposed method facilitates data communication between multiple publishers and subscribers. This work has implemented a system that publishes data from the equipment and additional sensors to a message broker. The subscribers can monitor and store the process data relayed by the broker. The system has been deployed and run for a film extrusion line to demonstrate the effectiveness.

This work proposes a flexible method for data communication between a film extrusion system and monitoring devices based on a message protocol called Message Queuing Telemetry Transport (MQTT).

This work aims at building a flexible data communication structure for a polymer processing machine by employing a publisher-subscriber based protocol ...

Determining Viral Disinfection Efficacy of Hot Water Laundering

This protocol provides an example of a laboratory process for conducting laundering studies that generate data on viral disinfection. While the protocol was developed for research during the coronavirus disease 2019 (COVID-19) pandemic, it is intended to be a framework, adaptable to other virus disinfection studies; it demonstrates the steps for preparing the test virus, inoculating the test material, assessing visual and integrity changes to the washed items due to the laundering process, and quantifying the reduction in viral load. Additionally, the protocol outlines the necessary quality control samples for ensuring the experiments are not biased by contamination and measurements/observations that should be recorded to track the material integrity of the personal protective equipment (PPE) items after multiple laundering cycles. The representative results presented with the protocol use the Phi6 bacteriophage inoculated onto cotton scrub, denim, and cotton face-covering materials and indicate that the hot water laundering and drying process achieved over a 3-log (99.9%) reduction in viral load for all samples (a 3-log reduction is the disinfectant performance metric in U.S. Environmental Protection Agency's Product Performance Test Guideline 810.2200). The reduction in viral load was uniform across different locations on the PPE items. The results of this viral disinfection efficacy testing protocol should help the scientific community explore the effectiveness of home laundering for other types of test viruses and laundering procedures.

In response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, a laboratory protocol was developed to test the viral disinfection efficacy of hot water laundering of cloth face coverings, cotton scrubs, and denim pants. The Phi6 virus (bacteriophage) was used as the organism to test disinfection efficacy.

This protocol provides an example of a laboratory process for conducting laundering studies that generate data on viral disinfection. While the protocol ...