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...

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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.

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

Abstract