Name: A Fabrication Method for Highly Stretchable Conductors with Silver Nanowires (Video) | JoVE Journal
Uploaded: 2016-01-21T15:00:00.000+00:00
Duration: 7 min 50 s
Description: Learn a simple fabrication method for highly stretchable conductors using silver nanowire thin films. This technique reduces silver usage while maintaining excellent conductivity and mechanical stability for stretchable electronics applications.

ai_agent_IP

ai_agent

maintenance

instantTrialDurationMinutes

isBiopharma

enableNewMyJoveSectionDesign

educationFeatures

seoMetaApi

ai_copilot_institution_blacklist

ai_chat_institution_blacklist

freeAccessWindow

ssoRoleCapture

scheduledMaintenanceBanner

joveLabsFeatures

disable_autoplay_for_bots

extended_trial_duration

5 minutes

The authors are grateful for the financial support from Ministry of Science and Technology.

1. Preparation of Silver Precursor Ink
<ol>
	<li>Add 1.85 g of diethanolamine (DEA) in 3.15 ml deionized water.</li>
	<li>Dissolve 0.15 g of silver nitrate in 5 ml deionized water.</li>
	<li>Mix the aqueous silver nitrate solution with DEA at a 1:1 volume ratio to have 10 ml silver precursor ink right before use.</li>
</ol>
2. Fabrication of Stretchable Conductive Thin Films
<ol>
	<li>Preparation of AgNW ink
	<ol>
		<li>Dilute 2 ml of 0.5 wt% AgNWs in isopropanol with 18 ml deionized water.</li>
		<li>Place it in ultrasonic bath for 30 sec at 25 &#176;C.</li>
	</ol>
	</li>
	<li>Fabrication of AgNW thin films by auto-spray coating
	<ol>
		<li>Cut standard microscope slides into pieces of size equal to 1&#215;2.5 cm2. Prepare 16 glass pieces of this size and clean them with ethanol-wetted lens cleaning tissue.</li>
		<li>Transfer 16 ml AgNW ink (from section 1) into the paint cup of the airbrush with a pipette. Mount the airbrush on a computer-controlled robot for spray coating.</li>
		<li>Place 8 of glass pieces in a 4&#215;2 arrangement on the stage and fix them with heat-resistant tapes. The total area of all glass substrates on the stage is 4&#215;5 cm2.</li>
		<li>Set working pressure and heating stage temperature at 3 bar and 100 &#176;C, separately.</li>
		<li>Open the robot control software. Click to select brush motion command sequence under the &#34;Command&#34; column. Type in necessary input parameters to complete the auto-spraying program as shown in Figure 1. Run the program. 
		Note: The &#34;Line Speed&#34; command makes the airbrush travel at 200 mm/sec. By the &#34;Brush Area&#34; command, the airbrush moves back and forth in the direction of the short side of the glass substrate array while the stage moves along the direction of the long side and the space between two strokes is 5 mm. The &#34;Line Start&#34; and &#34;Line End&#34; commands determine the positions of starting and end points of the auto-spraying operation. The positions of them depend on the position of the glass substrate array on the stage. The &#34;Wait Point&#34; command sets a waiting time of 20 sec in the end of each auto-spraying cycle. &#34;Loop Address&#34; command enables multiple spray cycles and the number of auto-spraying cycles is 15 times. More detailed instruction of the commands can be found in the manufacturer&#39;s protocol.</li>
		<li>Change the number of auto-spraying cycles into 30 times. Repeat steps 2.2.3 - 2.2.5 to fabricate AgNW thin films of 30 spraying cycles.</li>
		<li>After spray coating, bake silver nanowire thin films on a hot plate at 120 &#176;C for 10 min.</li>
	</ol>
	</li>
	<li>&#160;Chemical soldering process
	<ol>
		<li>Cast 400 &#956;l of silver precursor ink over each spray-coated silver nanowire thin film on the glass substrate.</li>
		<li>Bake the films on a hot plate at 100 &#176;C for 40 min.</li>
		<li>Rinse the reactive coatings carefully with deionized water to remove unreactive chemical residues and air-dry the coated films.</li>
	</ol>
	</li>
	<li>Cast-peeling process
	<ol>
		<li>&#160;Cast 200 &#956;l commercially available water-based PU emulsion over each silver nano-composite thin film on the glass substrate.</li>
		<li>Air-dry the films for 10 hr to ensure full solidification.</li>
		<li>Peel off the samples from the glass substrates as free standing composite films.</li>
	</ol>
	</li>
</ol>
3. Characterization
<ol>
	<li>&#160;Stretching test
	<ol>
		<li>Turn on the linear motorized stage and wait 10 min for the machine to warm up.</li>
		<li>Open the stage control software. Set the number of the moving steps of the motor as 8,000. Click &#34;X+&#34; in the stage control software to move the mobile stage until it touches the fixed stage and click &#34;SET 0&#34; to set the position of the mobile stage as zero in the stage control software. 
		Note: The mobile stage moves 0.00125 mm in one step of the motor. For example, the mobile stage moves 1 cm if the motor moves 8,000 steps. The plus sign of &#34;X+&#34; means that the mobile stage moves in the direction of approaching fixed stage while the negative sign of &#34;X-&#34; means moving away from the fixed stage.</li>
		<li>Click &#34;X-&#34; to move the mobile stage to leave 1 cm space between the mobile and fixed stage. Secure both ends of the sample with wired holders onto the stages. Thereby, the stretching area of the sample is 1&#215;1 cm2. The setup of stretching machine is shown in Figure 2.</li>
		<li>Use the alligator clips, which are the other ends of the wiring cables to the stage holders (Figure 2), to connect to the digital multimeter for resistance measurements.</li>
		<li>Set the number of the moving steps of the motor as 800. Click &#34;X-&#34; to move the mobile stage 1 mm (10% strain) away from the fixed stage to stretch the sample and record the resistance. Repeat this step until the resistance increases significantly (~150% strain).</li>
	</ol>
	</li>
	<li>Stability test
	<ol>
		<li>Prepare the test as in steps 3.1.2 - 3.1.4.</li>
		<li>Open the digital multimeter software. Connect the digital multimeter to the computer. Long press the &#34;REL &#916;&#34; button on the digital multimeter until a computer icon appears in the upper left corner of the digital multimeter monitor. Click &#34;USB connection&#34; in the digital multimeter software and the software starts to record measured resistances.</li>
		<li>Enter commands into the input fields in the program panel of the stage control software as shown in Figure 3. The command &#34;:U-4000&#34; means to move the mobile stage 4,000 steps away from the fixed stage while the command &#34;:U4000&#34; means to move the mobile stage 4,000 steps back to the fixed stage (4,000 for 50% strain, 8,000 for 100% strain). The number of stretching cycles is 15 times. The default speed of the mobile stage is 1 mm/sec.</li>
		<li>Click &#34;Run 123&#34; in the program panel of the stage control software to execute the automatic program. The mobile stage moves in a reciprocating motion to stretch the sample with elongation cycles of triangular waveform.</li>
		<li>Click the save icon in the multimeter software and export the data of the resistance response profiles as an .xls file.</li>
	</ol>
	</li>
	<li>LED lighting test
	<ol>
		<li>Prepare the test as in steps 3.1.2 - 3.1.3. Connect the wired holders in series with a LED and a power supply.</li>
		<li>Turn on the power supply. Increase the voltage to 9 V to light the LED.</li>
		<li>Click &#34;X-&#34; to move the mobile stage 1 mm (10% strain) away from the fixed stage to stretch the sample and take a picture to record the brightness of the LED. Repeat this step until the light of LED becomes dim. Be careful that the auto-exposure of the camera should be turned off while taking pictures.</li>
	</ol>
	</li>
</ol>

<ol><li>Rogers, J. A., Someya, T., Huang, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Materials+and+mechanics+for+stretchable+electronics%5BTitle%5D)+AND+%22Science%22%5BJournal%5D)">Materials and mechanics for stretchable electronics.</a> Science. 327 (5973), 1603-1607 (2010).</li>
<li>Mazzeo, A. D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Paper-based%2C+capacitive+touch+pads%5BTitle%5D)+AND+%22Adv.+Mater%22%5BJournal%5D)">Paper-based, capacitive touch pads.</a> Adv. Mater. 24 (21), 2850-2856 (2012).</li>
<li>Yang, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Silver+nanowires%3A+from+scalable+synthesis+to+recyclable+foldable+electronics%5BTitle%5D)+AND+%22Adv.+Mater%22%5BJournal%5D)">Silver nanowires: from scalable synthesis to recyclable foldable electronics.</a> Adv. Mater. 23 (27), 3052-3056 (2011).</li>
<li>Sekitani, T., Someya, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Stretchable%2C+Large-area+Organic+Electronics%5BTitle%5D)+AND+%22Adv.+Mater%22%5BJournal%5D)">Stretchable, Large-area Organic Electronics.</a> Adv. Mater. 22 (20), 2228-2246 (2010).</li>
<li>Lipomi, D. J., Tee, B. C., Vosgueritchian, M., Bao, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Stretchable+organic+solar+cells%5BTitle%5D)+AND+%22Adv.+Mater%22%5BJournal%5D)">Stretchable organic solar cells.</a> Adv. Mater. 23 (15), 1771-1775 (2011).</li>
<li>Liang, J., Li, L., Niu, X., Yu, Z., Pei, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Elastomeric+polymer+light-emitting+devices+and+displays%5BTitle%5D)+AND+%22Nat.+Photonics%22%5BJournal%5D)">Elastomeric polymer light-emitting devices and displays.</a> Nat. Photonics. 7 (10), 817-824 (2013).</li>
<li>White, M. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Ultrathin%2C+highly+flexible+and+stretchable+PLEDs%5BTitle%5D)+AND+%22Nat.+Photonics%22%5BJournal%5D)">Ultrathin, highly flexible and stretchable PLEDs.</a> Nat. Photonics. 7 (10), 811-816 (2013).</li>
<li>Chang, I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Performance+enhancement+in+bendable+fuel+cell+using+highly+conductive+Ag+nanowires%5BTitle%5D)+AND+%22Int.+J.+Hydrogen+Energ%22%5BJournal%5D)">Performance enhancement in bendable fuel cell using highly conductive Ag nanowires.</a> Int. J. Hydrogen Energ. 39 (14), 7422-7427 (2014).</li>
<li>Yan, C. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((An+Intrinsically+Stretchable+Nanowire+Photodetector+with+a+Fully+Embedded+Structure%5BTitle%5D)+AND+%22Adv.+Mater%22%5BJournal%5D)">An Intrinsically Stretchable Nanowire Photodetector with a Fully Embedded Structure.</a> Adv. Mater. 26 (6), 943-950 (2014).</li>
<li>Lee, M. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((High-performance%2C+transparent%2C+and+stretchable+electrodes+using+graphene-metal+nanowire+hybrid+structures%5BTitle%5D)+AND+%22Nano+Lett%22%5BJournal%5D)">High-performance, transparent, and stretchable electrodes using graphene-metal nanowire hybrid structures.</a> Nano Lett. 13 (6), 2814-2821 (2013).</li>
<li>Xu, F., Zhu, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Highly+conductive+and+stretchable+silver+nanowire+conductors%5BTitle%5D)+AND+%22Adv.+Mater%22%5BJournal%5D)">Highly conductive and stretchable silver nanowire conductors.</a> Adv. Mater. 24 (37), 5117-5122 (2012).</li>
<li>Yun, S., Niu, X., Yu, Z., Hu, W., Brochu, P., Pei, Q. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Compliant+silver+nanowire-polymer+composite+electrodes+for+bistable+large+strain+actuation%5BTitle%5D)+AND+%22Adv.+Mater%22%5BJournal%5D)">Compliant silver nanowire-polymer composite electrodes for bistable large strain actuation.</a> Adv. Mater. 24 (10), 1321-1327 (2012).</li>
<li>Lee, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Highly+stretchable+and+highly+conductive+metal+electrode+by+very+long+metal+nanowire+percolation+network%5BTitle%5D)+AND+%22Adv.+Mater%22%5BJournal%5D)">Highly stretchable and highly conductive metal electrode by very long metal nanowire percolation network.</a> Adv. Mater. 24 (25), 3326-3332 (2012).</li>
<li>Akter, T., Kim, W. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Reversibly+Stretchable+Transparent+Conductive+Coatings+of+Spray-Deposited+Silver+Nanowires%5BTitle%5D)+AND+%22ACS+Appl.+Mater.+Interfaces%22%5BJournal%5D)">Reversibly Stretchable Transparent Conductive Coatings of Spray-Deposited Silver Nanowires.</a> ACS Appl. Mater. Interfaces. 4 (4), 1855-1859 (2012).</li>
<li>Madaria, A., Kumar, A., Ishikawa, F., Zhou, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Uniform%2C+highly+conductive%2C+and+patterned+transparent+films+of+a+percolating+silver+nanowire+network+on+rigid+and+flexible+substrates+using+a+dry+transfer+technique%5BTitle%5D)+AND+%22Nano+Res%22%5BJournal%5D)">Uniform, highly conductive, and patterned transparent films of a percolating silver nanowire network on rigid and flexible substrates using a dry transfer technique.</a> Nano Res. 3 (8), 564-573 (2010).</li>
<li>Lee, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Room-Temperature+Nanosoldering+of+a+Very+Long+Metal+Nanowire+Network+by+Conducting-Polymer-Assisted+Joining+for+a+Flexible+Touch-Panel+Application%5BTitle%5D)+AND+%22Adv.+Funct.+Mater%22%5BJournal%5D)">Room-Temperature Nanosoldering of a Very Long Metal Nanowire Network by Conducting-Polymer-Assisted Joining for a Flexible Touch-Panel Application.</a> Adv. Funct. Mater. 23 (34), 4171-4176 (2013).</li>
<li>Tokuno, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Fabrication+of+silver+nanowire+transparent+electrodes+at+room+temperature%5BTitle%5D)+AND+%22Nano+Res%22%5BJournal%5D)">Fabrication of silver nanowire transparent electrodes at room temperature.</a> Nano Res. 4 (12), 1215-1222 (2011).</li>
<li>Garnett, E. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Self-limited+plasmonic+welding+of+silver+nanowire+junctions%5BTitle%5D)+AND+%22Nat.+Mater%22%5BJournal%5D)">Self-limited plasmonic welding of silver nanowire junctions.</a> Nat. Mater. 11 (3), 241-249 (2012).</li>
<li>Zhu, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Transferable+self-welding+silver+nanowire+network+as+high+performance+transparent+flexible+electrode%5BTitle%5D)+AND+%22Nanotechnology%22%5BJournal%5D)">Transferable self-welding silver nanowire network as high performance transparent flexible electrode.</a> Nanotechnology. 24 (10), 1321-1327 (2013).</li>
<li>Han, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Fast+Plasmonic+Laser+Nanowelding+for+a+Cu-Nanowire+Percolation+Network+for+Flexible+Transparent+Conductors+and+Stretchable+Electronics%5BTitle%5D)+AND+%22Adv.+Mater%22%5BJournal%5D)">Fast Plasmonic Laser Nanowelding for a Cu-Nanowire Percolation Network for Flexible Transparent Conductors and Stretchable Electronics.</a> Adv. Mater. 26 (33), 5808-5814 (2014).</li>
<li>Chen, S. P., Liao, Y. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Highly+stretchable+and+conductive+silver+nanowire+thin+films+formed+by+soldering+nanomesh+junctions%5BTitle%5D)+AND+%22Phys.+Chem.+Chem.+Phys%22%5BJournal%5D)">Highly stretchable and conductive silver nanowire thin films formed by soldering nanomesh junctions.</a> Phys. Chem. Chem. Phys. 16 (37), 19856-19860 (2014).</li>
<li>Chen, S. P., Kao, Z. K., Lin, J. L., Liao, Y. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Silver+conductive+features+on+flexible+substrates+from+a+thermally+accelerated+chain+reaction+at+low+sintering+temperatures%5BTitle%5D)+AND+%22ACS+Appl.+Mater.+Interfaces%22%5BJournal%5D)">Silver conductive features on flexible substrates from a thermally accelerated chain reaction at low sintering temperatures.</a> ACS Appl. Mater. Interfaces. 4 (12), 7064-7068 (2012).</li>
</ol>

The authors have nothing to disclose.

The chemical soldering process can help reinforce the contact between silver nanowires. As shown in Figure 4b, the wire/wire junctions are covered with silver after applying the reactive silver ink over the spray coated AgNW thin film. The silver recovery relies strongly on the formaldehyde generated from DEA degradation, and thus the soldering process or silver reduction can be accelerated with increasing temperature.22 Because the metal surfaces of AgNWs provide effective electron exchange s...

Deformable electronic devices with large stretchability have been identified as critical parts to the realization of wearable and portable electronics in the next generation.1 Those stretchable electronic devices not only show great flexibility as those electronic devices on plastic sheets,2, 3 but also exhibit excellent performance under severe stretching or twisting conditions.4 To realize the stretchable electronics, materials with great electric performance under large deformation is needed. Recent advancements in material sciences have shown the possibility to synthesize such functional materials and have used them to design stretchable optoelectronic devices 5-9 with great tolerance to complex shape deformations. Among all the electronic functional materials, stretchable conductors are necessary to supply electrical power to those optoelectronic devices and thus are of critical importance for device performance. Because regular conducting materials, like metal or indium tin oxide, lack of mechanical robustness under large deformation, interconnects made of these materials are unable to exhibit good electrical conductivity under stretching process. Thus, elastic substrates covered with a thin layer of flexible conductive materials, such as carbon nanotube,1 graphene,10 or AgNWs,11-14 are designed for conductors with excellent stretchability. Because of the high bulk conductivity, AgNW thin films have been shown to be the most promising material for composite stretchable conductors.13 The percolating networks of AgNW thin films can effectively accommodate large elastic deformations in stretching process with great electrical conductance, and are considered as a promising stretchable electrode candidate. To implement AgNW thin films as stretchable conductors, it is necessary to have effective electrical contacts between AgNWs. After liquid deposition and drying on substrate surfaces, AgNWs regularly stack together to form a percolating mesh with loose contact points, which yield in large electrical resistances. Thus, one needs to anneal the contacts between nanowires by high-temperature or high-pressure annealing methods15-20 to reduce the contact resistances.
In contrast to these annealing processes in the literature, here, we will demonstrate a simple chemical method to anneal AgNW network connections under regular laboratory conditions.21 The fabrication process is shown in Figure 4A. A reactive ink is used to sinter the spray coated AgNW thin films on a glass plate. After reaction, the contacts between nanowires are covered with silver and hence the AgNW network is soldered chemically together. A cast-and-peel method is then used to transfer the soldered AgNW network to a stretchable PU substrate to form a composite conductor, which can exhibit no obvious change in electrical conductivity even at large tensile strain of 120%.

<table><tbody><tr><td>Silver nanowire</td><td>Sigma-Aldrich</td><td>778095-25ML</td><td>AgNW, 120 nm in diameter and 20-50 mm in length, 0.5 wt% in IPA</td></tr><tr><td>Silver nitrate crystal</td><td>Macron Fine Chemicals</td><td>MK216903</td><td></td></tr><tr><td>Diethanolamine</td><td>Sigma-Aldrich</td><td>D8885-500G</td><td></td></tr><tr><td>Polyurethane emulsion</td><td>First Chemical</td><td>20130326036</td><td>35 wt% water-based anionic polyester-polyurethane emulsion</td></tr><tr><td>Airbrush</td><td>Taiwan Airbrush &amp;amp; Equipment</td><td>AFC-sensor&amp;nbsp;</td><td></td></tr><tr><td>Desktop robot</td><td>Dispenser Tech</td><td>DT-200&amp;nbsp;</td><td></td></tr><tr><td>Digital dispenser controller</td><td>Dispenser Tech</td><td>9000E&amp;nbsp;</td><td></td></tr><tr><td>Auto-spraying program</td><td>Dispenser Tech</td><td>Smart robot edit version 3.0.0.5</td><td></td></tr><tr><td>Air compressor&amp;nbsp;</td><td>PUMA Industrial</td><td>NCS-10&amp;nbsp;</td><td></td></tr><tr><td>Linear motorized stage</td><td>TANLIAN E-O</td><td>Customized</td><td></td></tr><tr><td>Stage control software</td><td>TANLIAN E-O</td><td>Customized</td><td></td></tr><tr><td>Digital multimeter</td><td>HILA INTERNATIONAL</td><td>DM-2690TU</td><td></td></tr><tr><td>Digital multimeter software</td><td>HILA INTERNATIONAL</td><td>NA</td><td></td></tr><tr><td>Power supply</td><td>CHERN TAIH</td><td>CT-605</td><td></td></tr><tr><td>LED</td><td>PChome</td><td>M08330766</td><td>http://www.pcstore.com.tw/sun-flower/M08330766.htm</td></tr></tbody></table>

a fabrication method for highly stretchable conductors with silver nanowires

A Fabrication Method for Highly Stretchable Conductors with Silver Nanowires

Stretchable electronics are identified as a key technology for electronic applications in the next generation. One of the challenges in fabrication of stretchable electronic devices is the preparation of stretchable conductors with great mechanical stability. In this study, we developed a simple fabrication method to chemically solder the contact points between silver nanowire (AgNW) networks. AgNW nanomesh was first deposited on a glass slide via spray coating method. A reactive ink composed of silver nanoparticle (AgNPs) precursors was applied over the spray coated AgNW thin films. After heating for 40 min, AgNPs were preferentially generated over the nanowire junctions to solder the AgNW nanomesh, and reinforced the conducting network. The chemically modified AgNW thin film was then transferred to polyurethane (PU) substrates by casting method. The soldered AgNW thin films on PU exhibited no obvious change in electrical conductivity under stretching or rolling process with elongation strains up to 120%.

The morphology of the AgNW thin film after chemical soldering process is shown in Figure 4B. Recovered AgNPs preferentially grow on the surface of AgNWs and wrap over the wire/wire junctions. Figure 5 shows the variation in sheet resistance with applied elongation strains for the unsoldered and the soldered thin films containing different amount of AgNWs. After the chemical soldering process, AgNW thin film conductors can maintain high conductivity under ...

A simple synthesis method is used to chemically solder silver nanowire thin film to fabricate highly stretchable and conductive metal conductors.

Stretchable electronics are identified as a key technology for electronic applications in the next generation. One of the challenges in fabrication of ...

The overall goal of this procedure is to provide a simple method to fabricate highly stretchable conductors for applications in stretchable electronics. This method can help answer key questions in developing stretchable electronics such as the mechanical of connecting conductors. The main advantage of this technique is that it's a simple fabrication method.And the amount of silver there was in the fabrication of the conductors can be greatly reduced. To begin, prepare 10 milliliters of fresh aqueous silver nitrate solution, with DEA at a one to one volume ratio. Next, fabricate the stretchable conductive thin films.First, make the silver nanowire ink by diluting two milliliters of 0.5%silver nanowire in isopropanol, into 18 milliliters of water. Sonicate this mixture for 30 seconds. Next, use a pipette to transfer 16 milliliters of this mixture to an airbrush.Mount the loaded airbrush to a computer-controlled robot. Then, on the heated airbrushing stage, arrange eight glass rectangles to cover a four by five centimeter area. Use heat-resistant tape to fix the slides in place.Then, set the stage to 100 degrees Celsius, and set the airbrush to three bars. Now, in the software control of the robot, select the brush motion command sequence under the command column. Then, input the necessary parameters to complete the auto spraying program, and run the program.Consult the text protocol for more details. After spraycoating the glass, bake the silver nanowire thin films on a hot plate at 120 degrees Celsius for 10 minutes. Once baked, cast 400 microliters of the prepared silver precursor ink over the thin film.Then bake the films on a hot plate set to 100 degrees Celsius for 40 minutes. Later, carefully rinse the coatings under deionized water to remove the unreacted chemical residues. Then, air-dry the coated films.The next step is to cast 200 microliters of water-based PU emulsion over the silver nano-composite thin films. Then, let the films air-dry for 10 hours so they are fully solidified. Once fully solidified, peel the samples off the glass using forceps, and proceed with testing them.First, execute a stretch test. Begin by warming up a linear motorized stage. Now, in the software control of the stage, set the number of the moving steps for the motor to 8000.Then, click X+in the stage control software to move the mobile stage until it touches the fixed stage. When contact is made, click Set 0"in the stage control software. Then, click X-to move the mobile stage backward.Move the stage until there is a one centimeter gap between the two stages. Now, secure the sample across the gap with wired holders. This creates a testable one by one centimeter area.Next, connect the alligator clips to the digital multimeter, and record the resistance across the test area. Then, set the number of the moving steps of the motor to 800 and click X-to move the mobile stage one millimeter further away from the fixed stage to create a 10%strain on the sample. After producing a 10%strain, record the resistance.Repeat this step until the resistance increases significantly, which may require a strain of 150%Then, proceed with the next sample or the next test. Next, conduct a stability test. Setup is like the stretch test, however, for this test, connect the multimeter to a computer so the computer can record the data.In the stage control software, key in the number of cycles, and click on run 1 2 3"in the program panel to execute the stability test. This moves the mobile stage in a reciprocating motion to stretch the sample, with elongation cycles in triangular wave form. The final test is the LED lighting test.Set up the test material as before, and connect the wired holders in series with an LED and a power supply. Now, increase the power supply from zero to nine volts. This should light up the LED.Then, in the software, create strain as done for the strain test, until the LED becomes dim. Once a sample passes all these tests, it can be considered an effective conductor in the applications of stretchable electronics. The morphology of the silver nanowire thin film after the chemical soldering process shows that the recovered silver nanoparticles preferentially grow on the surface of silver nanowire and wrap over the wire-wire junctions.Elongation strain was placed on unsoldered and soldered thin films, containing different amounts of silver nanowire. Both showed sheet resistance below 100 ohms, when strains below 120%were applied. The composite stretchable conducting thin films showed great mechanical stability in this dynamic deformation process.When subjecting the thin film to elongation cycles in a triangular waveform at a fast strain rate, no obvious resistance changes were observed at strain amplitudes of 50%When the strain amplitude was 100%the peak resistance increased with the pulsation cycles. After the pulsation stopped, the resistance of the film returned to the original value. This method can produce highly stretchable conductors to serve us in effective interconnect for next generation stretchable electronics.

a-fabrication-method-for-highly-stretchable-conductors-with-silver

Research

JoVE Journal

Engineering

Planar and three-dimensional printing of conductive metallic inks is described. Our approach provides new avenues for fabricating printed electronic, optoelectronic, and biomedical devices in unusual layouts at the microscale.

Planar and Three-Dimensional Printing of Conductive Inks

Femtosecond-laser direct-writing is frequently used to create three-dimensional (3D) patterns in polymers and glasses. However, patterning metals in 3D remains a challenge. We describe a method for fabricating silver nanostructures embedded inside a polymer matrix using a femtosecond laser centered at 800 nm.

A Method to Fabricate Disconnected Silver Nanostructures in 3D

The fabrication of electrically addressable, high-aspect-ratio (&gt; 1000:1) metal nanowires separated by gaps of single nanometers using either sacrificial layers of aluminum and silver or self-assembled monolayers as templates is described. These nanogap structures are fabricated without a clean room or any photo- or electron-beam lithographic processes by a form of edge lithography known as nanoskiving.

Fabricating Nanogaps by Nanoskiving

Silver nanowires can simultaneously transport electrons and optical information in the form of surface plasmons. A procedure is described here to realize such a shared circuitry and the limitations at propagating both information carriers are evaluated.

Evaluating Plasmonic Transport in Current-carrying Silver Nanowires

This protocol describes a solution-based fabrication strategy for high-performance, flexible, transparent electrodes with fully-embedded, thick metal mesh. Flexible transparent electrodes fabricated by this process demonstrate among the highest reported performances, including ultra-low sheet resistance, high optical transmittance, mechanical stability under bending, strong substrate adhesion, surface smoothness, and environmental stability.

Scalable Solution-processed Fabrication Strategy for High-performance, Flexible, Transparent Electrodes with Embedded Metal Mesh

In this paper, flow assisted dielectrophoresis is demonstrated for the self-assembly of nanowire devices. The fabrication of a silicon nanowire field effect transistor is shown as an example.

Flow-assisted Dielectrophoresis: A Low Cost Method for the Fabrication of High Performance Solution-processable Nanowire Devices

Here, we present a protocol to produce high-resolution conductive patterns using electrohydrodynamic (EHD) jet printing. The protocol includes two modes of EHD jet printing: the continuous near-field electrospinning (NFES) and the dot-based drop-on-demand (DOD) EHD printing.

High-resolution Patterning Using Two Modes of Electrohydrodynamic Jet: Drop on Demand and Near-field Electrospinning

Here, we present a protocol to quickly and reproducibly generate biologically inspired, biodegradable articifical antigen presenting cells (aAPC) with tunable size, shape, and surface protein presentation for T cell expansion ex vivo or in vivo.

Fabrication of Anisotropic Polymeric Artificial Antigen Presenting Cells for CD8+ T Cell Activation

In this protocol, we describe the detailed experimental procedure for the fabrication of a robust nanoscale contact between a silver nanowire network and CdS buffer layer in a CIGS thin-film solar cell.

Fabrication of Robust Nanoscale Contact between a Silver Nanowire Electrode and CdS Buffer Layer in Cu(In,Ga)Se2 Thin-film Solar Cells

In this work, we describe a protocol to fabricate iron nanowires, including the formation of the porous alumina membrane that is used as the template, electrodeposition into templates using electrolyte solution, and the release of the nanowires into the solution.

Iron Nanowire Fabrication by Nano-Porous Anodized Aluminum and its Characterization

Flexible electrodes have a wide range of applications in soft robotics and wearable electronics. The present protocol demonstrates a new strategy to fabricate highly stretchable electrodes with high resolution via lithographically defined microfluidic channels, which paves the way for future high-performance soft pressure sensors.

Microfluidic Channel-Based Soft Electrodes and Their Application in Capacitive Pressure Sensing

Learn a simple fabrication method for highly stretchable conductors using silver nanowire thin films. This technique reduces silver usage while maintaining excellent conductivity and mechanical stability for stretchable electronics applications.

A Fabrication Method for Highly Stretchable Conductors with Silver Nanowires

Explore More Videos