Name: a fabrication and measurement method for a flexible ferroelectric element based on van der waals heteroepitaxy
Uploaded: 2018-04-08T14:00:00
Description: Watch this Scientific Journal Video about A Fabrication and Measurement Method for a Flexible Ferroelectric Element Based on Van Der Waals Heteroepitaxy at JoVE.com

This work was supported by National Natural Science Foundation of China (Grant Nos. 11402221 and 11502224), the State Key Laboratory of Intense Pulsed Radiation simulation and effect (SKLIPR1513) and the Hunan Provincial Key Research and Development Plan (No. 2016WK2014).

1. Fabricating Flexible PZT Thin Films
<ol>
	<li>Cut a 1 cm x 1 cm mica substrate from a mica sheet with scissors.</li>
	<li>Fix this 1 cm x 1 cm mica substrate on a desk using double-sided tape.</li>
	<li>Use tweezers to peel-off the mica layer-by-layer until the desired thickness (50 &#181;m), measured with a micrometer.</li>
	<li>Paste this freshly cleaved mica substrate on a 5&#39;&#39; substrate holder using a thin layer of silver paint and cure it at 120 &#176;C on a hot plate for 10 minutes to affix mica on subs...

<ol>
	<li>Kim, W. Y., Lee, H. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stable+ferroelectric+poly+(vinylidene+fluoride-trifluoroethylene)+film+for+flexible+nonvolatile+memory+application.">Stable ferroelectric poly (vinylidene fluoride-trifluoroethylene) film for flexible nonvolatile memory application.</a> IEEE Electron Device Letters. 33 (2), 260-262 (2012).</li><li>Mao, D., Quevedo-Lopez, M. A., Stiegler, H., Gnade, B. E., Alshareef, H. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimization+of+poly(vinylidene+fluoride-trifluoroethylene)+films+as+non-volatile+memory+for+flexible+electronics.">Optimization of poly(vinylidene fluoride-trifluoroethylene) films as non-volatile memory for flexible electronics.</a> Organic Electronics. 11 (5), 925-932 (2010).</li><li>Lee, G. G., 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=The+flexible+non-volatile+memory+devices+using+oxide+semiconductors+and+ferroelectric+polymer+poly(vinylidene+fluoride-trifluoroethylene).">The flexible non-volatile memory devices using oxide semiconductors and ferroelectric polymer poly(vinylidene fluoride-trifluoroethylene).</a> Applied Physics Letters. 99 (1), 012901-012903 (2011).</li><li>Kim, R. H., 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=Non-volatile+organic+memory+with+sub-millimeter+bending+radius.">Non-volatile organic memory with sub-millimeter bending radius.</a> Nature Communications. 5, 3583-3594 (2014).</li><li>Liu, J., 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=Fabrication+of+Flexible,+All-Reduced+graphene+oxide+non-volatile+memory+devices.">Fabrication of Flexible, All-Reduced graphene oxide non-volatile memory devices.</a> Advanced Materials. 25 (2), 233-238 (2013).</li><li>Ji, 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=Stable+switching+characteristics+of+organic+nonvolatile+memory+on+a+bent+flexible+substrate.">Stable switching characteristics of organic nonvolatile memory on a bent flexible substrate.</a> Advanced Materials. 22 (28), 3071-3075 (2010).</li><li>Ghoneim, M. T., 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=Thin+PZT-based+ferroelectric+capacitors+on+flexible+silicon+for+nonvolatile+memory+applications.">Thin PZT-based ferroelectric capacitors on flexible silicon for nonvolatile memory applications.</a> Advanced Electronic Materials. 1 (6), 1500045-1500054 (2015).</li><li>Ghoneim, M. T., Hussain, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Study+of+harsh+environment+operation+of+flexible+ferroelectric+memory+integrated+with+PZT+and+silicon+fabric.">Study of harsh environment operation of flexible ferroelectric memory integrated with PZT and silicon fabric.</a> Applied. Physics. Letters. 107 (5), 052904-052908 (2015).</li><li>Zuo, Z., 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=Preparation+and+ferroelectric+properties+of+freestanding+Pb(Zr,Ti)O3+thin+membranes.">Preparation and ferroelectric properties of freestanding Pb(Zr,Ti)O3 thin membranes.</a> Journal of Physics D: Applied Physics. 45 (18), 185302-185306 (2012).</li><li>Kingon, A. I., Srinivasan, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lead+zirconate+titanate+thin+films+directly+on+copper+electrodes+for+ferroelectric,+dielectric+and+piezoelectric+applications.">Lead zirconate titanate thin films directly on copper electrodes for ferroelectric, dielectric and piezoelectric applications.</a> Nature Materials. 4 (3), 233-237 (2005).</li><li>Shelton, C. T., Gibbons, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epitaxial+Pb(Zr,Ti)O3+thin+films+on+flexible+substrates.">Epitaxial Pb(Zr,Ti)O3 thin films on flexible substrates.</a> Journal of the American Ceramic Society. 94 (10), 3223-3226 (2011).</li><li>Rho, J., 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=PbZrxTi1&#8722;xO3+Ferroelectric+thin-film+capacitors+for+flexible+nonvolatile+memory+applications.">PbZrxTi1&#8722;xO3 Ferroelectric thin-film capacitors for flexible nonvolatile memory applications.</a> IEEE Electron Device Letters. 31 (9), 1017-1019 (2010).</li><li>Bretos, I., 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=Activated+Solutions+Enabling+Low-Temperature+processing+of+functional+ferroelectric+oxides+for+flexible+electronics.">Activated Solutions Enabling Low-Temperature processing of functional ferroelectric oxides for flexible electronics.</a> Advanced Materials. 26 (9), 1405-1409 (2014).</li><li>Tsagarakis, E. D., Lew, C., Thompson, M. O., Giannelis, E. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanocrystalline+barium+titanate+films+on+flexible+plastic+substrates+via+pulsed+laser+annealing.">Nanocrystalline barium titanate films on flexible plastic substrates via pulsed laser annealing.</a> Applied Physics Letters. 89 (20), 202910-202912 (2006).</li><li>Bakaul, S. R., 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=High+speed+epitaxial+perovskite+memory+on+flexible+substrates.">High speed epitaxial perovskite memory on flexible substrates.</a> Advanced Materials. 29 (11), 1605699-1605703 (2017).</li><li>Li, C. I., 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=Van+der+Waal+epitaxy+of+flexible+and+transparent+VO2+film+on+muscovite.">Van der Waal epitaxy of flexible and transparent VO2 film on muscovite.</a> Chemistry of Materials. 28 (11), 3914-3919 (2016).</li><li>Ma, C. H., 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=Van+der+Waals+epitaxy+of+functional+MoO2+film+on+mica+for+flexible+electronics.">Van der Waals epitaxy of functional MoO2 film on mica for flexible electronics.</a> Applied Physics Letters. 108 (25), 253104-253108 (2016).</li><li>Bitla, 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=Oxide+heteroepitaxy+for+flexible+optoelectronics.">Oxide heteroepitaxy for flexible optoelectronics.</a> ACS Applied Materials &amp; Interfaces. 8 (47), 32401-32407 (2016).</li><li>Wu, P. C., 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=Heteroepitaxy+of+Fe3O4/muscovite:+A+new+perspective+for+flexible+spintronics.">Heteroepitaxy of Fe3O4/muscovite: A new perspective for flexible spintronics.</a> ACS Applied Materials &amp; Interfaces. 8 (49), 33794-33801 (2016).</li><li>Jiang, J., 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=Flexible+ferroelectric+element+based+on+van+der+Waals+heteroepitaxy.">Flexible ferroelectric element based on van der Waals heteroepitaxy.</a> Science Advances. 3 (6), e1700121-e1700128 (2017).</li><li>Amrillah, T., 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=Flexible+multiferroic+bulk+heterojunction+with+giant+magnetoelectric+coupling+via+van+der+waals+epitaxy.">Flexible multiferroic bulk heterojunction with giant magnetoelectric coupling via van der waals epitaxy.</a> ACS Nano. 11 (6), 6122-6130 (2017).</li><li>Bitla, Y., Chu, Y. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MICAtronics:+A+new+platform+for+&#64258;exible+X-tronics.">MICAtronics: A new platform for &#64258;exible X-tronics.</a> Flat Chem. 3, 26-42 (2017).</li><li>Chu, Y. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Van+der+Waals+oxide+heteroepitaxy.">Van der Waals oxide heteroepitaxy.</a> Quantum Materials. 2 (1), 67-71 (2017).</li></ol>

The key step in the fabrication of ferroelectric elements lies in the use of a clean and even/flat substrate surface. Though freshly cleaved mica surface is atomically smooth, it is necessary to pay attention to preventing surfaces from suffering visible splintering, split layers, cracks, inclusions, etc. After deposition of the PZT layer, the sample was cooled under a high oxygen pressure (200-500 Torr) to reduce the oxygen vacancies. Ex situ top platinum electrodes were deposited via a predefined mesh...

The successful fabrication of flexible nonvolatile memory elements (NVME) plays a key role in exploiting the full potential of flexible electronics. NVME shall feature light weight, low cost, low-power consumption, fast speed and high storage density capabilities besides data storage, information processing and communication. Perovskite Pb (Zr,Ti)O3 (PZT) acts as a popular system for such applications considering its large polarization, fast polarization switching, high Curie temperature, low coercive field and high piezoelectric coefficient. In ferroelectric nonvolatile memories, an external voltage pulse can switch the two remnant polarizations between two stable directions, represented by &#39;0&#39; and &#39;1&#39;. It is non-volatile, and the write/read process can be completed within nanoseconds. NVME based on organic1,2,3,4,5,6 and inorganic7,8,9,10,11,12,13,14,15 ferroelectric materials have been attempted on flexible substrates. However, such integration is limited by not only the substrates&#39; inability of high-temperature growth but also the degraded device performance, current leakage and electrical shorting due to their rougher surfaces. Despite promising results, alternate strategies like the thinning of substrate8 and the epitaxial layer transfer on a flexible substrate15 suffer restricted viability in view of the sophisticated multistep process, the unpredictability of transfer, and the limited applicability.
For the aforementioned reasons, it is critical to explore an appropriate substrate that is able to overcome limited thermal and operational stabilities of soft substrates to further advance flexible electronics. A natural muscovite mica (KAl2(AlSi3O10)(OH)2) substrate with unique features like atomically smooth surfaces, high thermal stability, chemical inertness, high transparency, mechanical flexibility, and compatibility with current fabrication methods can be used to effectively deal with these issues. More so, the two-dimensional layered structure of monoclinic mica supports van der Waals epitaxy, which mitigates lattice and thermal matching conditions, thereby significantly suppressing the substrate clamping effect. These advantages have been exploited in the direct growth of functional oxides16,17,18,19,20,21,22,23 on muscovite recently, in view of flexible device applications.
Herein, we describe a protocol to directly grow epitaxial yet flexible lead zirconium titanate (PZT) thin films on muscovite mica. This is achieved through a pulsed laser deposition process relying on the versatile properties of mica, resulting in van der Waals heteroepitaxy. Such fabricated structures retain all the superior properties of epitaxial PZT on rigid single crystalline substrates and exhibits excellent thermal and mechanical stabilities. This simple and reliable approach provides a technological advantage over multistep-transfer and substrate thinning strategies and facilitates the development of much-awaited flexible yet single-crystalline non-volatile memory elements prerequisite for next-generation smart devices with high performance.

<table border="0" cellpadding="0" cellspacing="0" width="1114">
	<tbody>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Equipment</td>
			<td style="width:387px;"></td>
			<td style="width:344px;"></td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">hot plate</td>
			<td style="width:387px;">Polish</td>
			<td style="width:344px;">P-20</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;">PLD system</td>
			<td>PVD products</td>
			<td>PLD 5000</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Ferroelectric test system&#160;</td>
			<td>Radiant Technologies Precisions workstations&#160;</td>
			<td>RT66A</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Semiconductor device analyzer&#160;</td>
			<td>Agilent&#160;</td>
			<td>B1500A</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Bending molds</td>
			<td>home-made</td>
			<td></td>
			<td>Machined teflon material</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Bending stage</td>
			<td>home-built</td>
			<td></td>
			<td>Labview interfaced setup which provides a prescise displacemnt as small as 1 micrometer</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Sputtering system</td>
			<td>Beijing&#160;Elaborate</td>
			<td>ETD-3000</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">Materials</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">mica(001) sheets</td>
			<td>Nilaco corporation&#160;</td>
			<td>990066</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">conductive silver paint</td>
			<td>Ted Pella, INC</td>
			<td>No.16033</td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">CoFe2O4 target</td>
			<td>Kurt J.Lesker</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">SrRuO3 target</td>
			<td>Kurt J.Lesker</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;">PbZr0.2Ti0.8O3 target</td>
			<td>Kurt J.Lesker</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:216px;">Pt target</td>
			<td>Hefei Ke jing</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

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.

The epitaxial PZT/SRO/CFO/mica thin films were deposited with the pulsed laser deposition technique as outlined in Step 1. Figure 1 shows the growth scheme and Figure 2 shows an actual flexible NVM element based on the PZT.

Mechanical stability is a crucial aspect of flexible device application. The macroscopic ferroelectric performance of the heterostructure ag...

Watch this Scientific Journal Video about A Fabrication and Measurement Method for a Flexible Ferroelectric Element Based on Van Der Waals Heteroepitaxy at JoVE.com

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

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 ...

A Fabrication and Measurement Method for Flexible Ferroelectric Element based on van der Waals Heteroepitaxy.Introduction. Fabricating Flexible PZT Thin Films. Cut a one centimeter by one centimeter mica substrate from a mica sheet with scissors.Fix this one centimeter by one centimeter mica substrate on a desk, using double-sided tape. Use tweezers to peel off the mica, layer by layer, until the desired thickness, measured with a micrometer. Paste this freshly-cleaved mica substrate on a five inch substrate holder, using a thin layer of silver paint, and cure it at 120 centigrade on a hot plate for 10 minutes to affix mica on a substrate firmly.Put the PLD substrate holder into the PLD chamber. Select the repetition rate and the laser energy. Move the focusing lens to the set position.Open the shatter and deposit a five millimeter CFO thin film as the buffer layer, by triggering the laser. Deposit a 20 to 18 millimeter SRO on SAFO buffer layer as the bottom electrode for the subsequent electrical performance tests, by triggering the laser. Deposit a 115 millimeter PZT thin film on the top of SRO bottom electrode, by triggering the laser.Vent the chamber using a tube, and remove the PZT on mica sample when the temperature reaches room temperature. Put the sample on a piece of glass. Put a pre-designed mesh with 200 micrometer diameter on top of the sample.Fix the mesh well and put mesh sample into the sputtering chamber. Use CD sputtering to deposit platinum top electrodes on the film. Remove the sample after sputtering.Use a knife or 20%hydrofluoric acid to remove nearly one millimeter by one millimeter PZT section. This is to uncover the bottom SRO electrode and form many small flexible ferroelectric capacitors. Paint a coat of conductive silver on the exposed SRO to increase the electrical conductivity of the bottom SRO electrode.Ensure that the conductive silver can contact the exposed SRO. Ferroelectric Characterization Bending Test. On the back side of the flexible sample, glue a piece of paper with the same size as the sample, for easy transfer of the sample from one stage to another.Place the PZT omega on a tester boat of the ferroelectric tester system in a semiconductor device analyzer. Put one measurement probe of the ferroelectric tester system and the semiconductor device analyzer on the platinum top electrode, and then put the other measurement probe on the silver SRO layer to give the polarization electric field hysteresis loops and the capacitor's electric field curves while the sample is unbent. Measure the P hysteresis loops with the two probes at a two kilohertz frequency and at four Watts.Measure the CE curves with the two probes at a one megahertz frequency and add four Watts. Remove the ambient sample. Secure the flexible PZT or mica thin film on the disable mode using double-sided tape.Take care to avoid the slipping or the gliding of the mica during the measurements. Mount it on the tester board of the ferroelectric tester system and the semiconductor device analyzer. Put one probe on the platinum top electrode while the other probe touches the bottom SRO electrode through the silver coding similar to the configuration used earlier.Measure the P-hysteresis loops and the CE curves under various tinsile and compressive bending radium. Measure the P-hysteresis loops with the two probes at a two kilohertz frequency and add four Watts. Measure the CE curves with the two probes at a one megahertz frequency and add four Watts.Remove the flexible PZT sample when the PE and the CE measurements are completed. Ferroelectric Characterization Thermal Stability. Put the PZT or mica on the tester boat of the ferroelectric tester system and the semiconductor device analyzer.Put one measurement probe on the platinum top electrode and put the other measurement probe on the sera SrO layer. Open the temperature control system to heat the sample. Conduct the PE and the CE measurements at different temperatures.Turn off the heater assembly after the measurements are done. Ferroelectric Characterization Bending Cyclability Tests. Mount the flexible PZT or mica into the two grooves of this setup.Fix one end of the sample where it is bent from the other end with eight AVO model. Use a ruler to measure the PZT or mica lens along with the movement direction of the motor prior to the eight millimeter bending process. Calculate the movement to lens C to bend the sample five millimeter according to the formula where area is the lens of PZT or mica in a bent state.R is the bending radia and C is the movement lens of the motor. Set number of bending cycles 1, 000 in the computer. Click the start button to initiate the back and forth motor motion.Remove the sample and the major VPE to check whether the ferroelectric properties are retained. Representative Results. The epitecture of PZT, SRO, CFO mica thin films were deposited and were supposed to laser the position technique, as outlined in step one.Figure 1 shows the gross gain and Figure 2 shows an actual flexible MVM element best on the PZT. Mechanical stability is a crucial aspect of flexible device application. The microscope ferroelectric performance of the hetero structure against the mechanic flexing was evaluated on the both tensile and the compressive bending.Figure 7A and 7B show the PE and the CE hysteresis loops of the PZT capacitors and the various compressive and tensile bending radius. Figure 7C shows the constant of saturated polarization. Residual electric polarization could urge the strands.And the capacitance values within experimental errors and different bending radius. This results just that the PZT thin film capacitors maintain stable electric practice and the mechanical constraints required for the flexible electronic device application which was also tooked by the raman spectroscopy. The well saturated and the symmetric polarization electric field hysteresis loops and the capacitance electric field with the butterfly curves of the hetero structure measured at one megahertz and the temperature bending from 25 to 175 centigrade for a new device are shown in Fig 8A and 8B, respectively.This ferroelectric capacitor is at the best constant saturation polarization. A remnant of polarization occurs in field and the capacitance in the wider temperature range as shown in Figure 8C. The hetero structure also maintain high retention and endurance at room temperature as well as at 100 centigrade.This process imply that the PZT or mica hetero structure can have potential applications in high temperature electronic device. A series of cylability tests were carried out to validate the PZT or mica hetero structures for practical applications. Figure 9 shows PE loops before and after 1, 000 bending cycles in both tinsile and the compressive strain states.The PE loops at a different bending moves are displayed vertically for the sake of convenience. It is not worthy that the hetero structure retains it's ferroelectric behavior even after 1, 000 bending cycles at a bending radius of five millimeters respective of the natural bending strain.Conclusion.

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Engineering

Fabrication of High Contrast Gratings for the Spectrum Splitting Dispersive Element in a Concentrated Photovoltaic System

High contrast gratings are designed and fabricated and its application is proposed in a parallel spectrum splitting dispersive element that can improve the solar conversion efficiency of a concentrated photovoltaic system. The proposed system will also lower the solar cell cost in the concentrated photovoltaic system by replacing the expensive tandem solar cells with the cost-effective single junction solar cells. The structures and the parameters of high contrast gratings for the dispersive elements were numerically optimized. The large-area fabrication of high contrast gratings was experimentally demonstrated using nanoimprint lithography and dry etching. The quality of grating material and the performance of the fabricated device were both experimentally characterized. By analyzing the measurement results, the possible side effects from the fabrication processes are discussed and several methods that have the potential to improve the fabrication processes are proposed, which can help to increase the optical efficiency of the fabricated devices.

The fabrication of high contrast gratings as the parallel spectrum splitting dispersive element in a concentrated photovoltaic system is demonstrated. Fabrication processes including nanoimprint lithography, TiO2 sputtering and reactive ion etching are described. Reflectance measurement results are used to characterize the optical performance.

High contrast gratings are designed and fabricated and its application is proposed in a parallel spectrum splitting dispersive element that can improve ...

Fabrication Process of Silicone-based Dielectric Elastomer Actuators

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This manuscript shows the fabrication process for the manufacture of dielectric elastomer soft actuators based on silicone membranes. The three key stages of production are presented in detail: blade casting of thin silicone membranes; pad printing of compliant electrodes; and the assembly of all the components.

This contribution demonstrates the fabrication process of dielectric elastomer transducers (DETs). DETs are stretchable capacitors consisting of an ...

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%.

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 ...

Standardized Method for Measuring Collection Efficiency from Wipe-sampling of Trace Explosives

One of the limiting steps to detecting traces of explosives at screening venues is effective collection of the sample. Wipe-sampling is the most common procedure for collecting traces of explosives, and standardized measurements of collection efficiency are needed to evaluate and optimize sampling protocols. The approach described here is designed to provide this measurement infrastructure, and controls most of the factors known to be relevant to wipe-sampling. Three critical factors (the applied force, travel distance, and travel speed) are controlled using an automated device. Test surfaces are chosen based on similarity to the screening environment, and the wipes can be made from any material considered for use in wipe-sampling. Particle samples of the explosive 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) are applied in a fixed location on the surface using a dry-transfer technique. The particle samples, recently developed to simulate residues made after handling explosives, are produced by inkjet printing of RDX solutions onto polytetrafluoroethylene (PTFE) substrates. Collection efficiency is measured by extracting collected explosive from the wipe, and then related to critical sampling factors and the selection of wipe material and test surface. These measurements are meant to guide the development of sampling protocols at screening venues, where speed and throughput are primary considerations.

Optimized sampling protocols and the development of new wipe materials can be facilitated by standardized measurements of collection efficiency from wipe-sampling. Our approach for sampling trace explosives uses an automated device to control speed, force, and distance during wipe-sampling followed by extraction of collected explosives.

One of the limiting steps to detecting traces of explosives at screening venues is effective collection of the sample. Wipe-sampling is the most common ...

Experimental Implementation of a New Composite Fabrication Method: Exposing Bare Fibers on the Composite Surface by the Soft Layer Method

The bipolar plate is a key component in proton exchange membrane fuel cells (PEMFCs) and vanadium redox flow batteries (VRFBs). It is a multi-functional component that should have high electrical conductivity, high mechanical properties, and high productivity.
In this regard, a carbon fiber/epoxy resin composite can be an ideal material to replace the conventional graphite bipolar plate, which often leads to the catastrophic failure of the entire system because of its inherent brittleness. Though the carbon/epoxy composite has high mechanical properties and is easy to manufacture, the electrical conductivity in the through-thickness direction is poor because of the resin-rich layer that forms on its surface. Therefore, an expanded graphite coating was adopted to solve the electrical conductivity issue. However, the expanded graphite coating not only increases the manufacturing costs but also has poor mechanical properties.
In this study, a method to expose fibers on the composite surface is demonstrated. There are currently many methods that can expose fibers by surface treatment after the fabrication of the composite. This new method, however, does not require surface treatment because the fibers are exposed during the manufacture of the composite. By exposing bare carbon fibers on the surface, the electrical conductivity and mechanical strength of the composite are increased drastically.

A protocol to expose bare fibers on the composite surface by eliminating resin rich area is presented. The fibers are exposed during fabrication of the composites, not by the post surface treatment. The exposed carbon composites exhibit high electrical conductivity in the through-thickness direction and high mechanical property.

The bipolar plate is a key component in proton exchange membrane fuel cells (PEMFCs) and vanadium redox flow batteries (VRFBs). It is a multi-functional ...

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, ...

Cutting Procedures, Tensile Testing, and Ageing of Flexible Unidirectional Composite Laminates

Many body armor designs incorporate unidirectional (UD) laminates. UD laminates are constructed of thin (&#60;0.05 mm) layers of high-performance yarns, where the yarns in each layer are oriented parallel to each other and held in place using binder resins and thin polymer films. The armor is constructed by stacking the unidirectional layers in different orientations. To date, only very preliminary work has been performed to characterize the ageing of the binder resins used in unidirectional laminates and the effects on their performance. For example, during the development of the conditioning protocol used in the National Institute of Justice Standard-0101.06, UD laminates showed visual signs of delamination and reductions in V50, which is the velocity at which half of the projectiles are expected to perforate the armor, after ageing. A better understanding of the material property changes in UD laminates is necessary to comprehend the long-term performance of armors constructed from these materials. There are no current standards recommended for mechanically interrogating unidirectional (UD) laminate materials. This study explores methods and best practices for accurately testing the mechanical properties of these materials and proposes a new test methodology for these materials. Best practices for ageing these materials are also described.

The goal of the study was to develop protocols to prepare consistent specimens for accurate mechanical testing of high-strength aramid or ultra-high-molar-mass polyethylene-based flexible unidirectional composite laminate materials and to describe protocols for performing artificial ageing on these materials.

Many body armor designs incorporate unidirectional (UD) laminates. UD laminates are constructed of thin (&#60;0.05 mm) layers of high-performance yarns, ...

Implementation of a Nonlinear Microscope Based on Stimulated Raman Scattering

Stimulated Raman scattering (SRS) microscopy uses near-infrared excitation light; therefore, it shares many multi-photon microscopic imaging properties. SRS imaging modality can be obtained using commercial laser-scanning microscopes by equipping with a non-descanned forward detector with proper bandpass filters and lock-in amplifier (LIA) detection scheme. A schematic layout of a typical SRS microscope includes the following: two pulsed laser beams, (i.e., the pump and probe directed in a scanning microscope), which must be overlapped in both space and time at the image plane, then focused by a microscope objective into the sample through two scanning mirrors (SMs), which raster the focal spot across an x-y plane. After interaction with the sample, transmitted output pulses are collected by an upper objective and measured by a forward detection system inserted in an inverted microscope. Pump pulses are removed by a stack of optical filters, whereas the probe pulses that are the result of the SRS process occurring in the focal volume of the specimen are measured by a photodiode (PD). The readout of the PD is demodulated by the LIA to extract the modulation depth. A two-dimensional (2D) image is obtained by synchronizing the forward detection unit with the microscope scanning unit. In this paper, the implementation of an SRS microscope is described and successfully demonstrated, as well as the reporting of label-free images of polystyrene beads with diameters of 3 &#181;m. It is worth noting that SRS microscopes are not commercially available, so in order to take advantage of these characteristics, the homemade construction is the only option. Since SRS microscopy is becoming popular in many fields, it is believed that this careful description of the SRS microscope implementation can be very useful for the scientific community.

In this manuscript, the implementation of a stimulated Raman scattering (SRS) microscope, obtained by the integration of an SRS experimental set-up with a laser scanning microscope, is described. The SRS microscope is based on two femtosecond (fs) laser sources, a Ti-Sapphire (Ti:Sa) and synchronized optical parametric oscillator (OPO).

Stimulated Raman scattering (SRS) microscopy uses near-infrared excitation light; therefore, it shares many multi-photon microscopic imaging properties. ...

Fabricating van der Waals Heterostructures with Precise Rotational Alignment

In this work we describe a technique for creating new crystals (van der Waals heterostructures) by stacking distinct ultrathin layered 2D materials. We demonstrate not only lateral control but, importantly, also control over the angular alignment of adjacent layers. The core of the technique is represented by a home-built transfer setup which allows the user to control the position of the individual crystals involved in the transfer. This is achieved with sub-micrometer (translational) and sub-degree (angular) precision. Prior to stacking them together, the isolated crystals are individually manipulated by custom-designed moving stages that are controlled by a programmed software interface. Moreover, since the entire transfer setup is computer controlled, the user can remotely create precise heterostructures without coming into direct contact with the transfer setup, labeling this technique as &#8220;hands-free&#8221;. In addition to presenting the transfer set-up, we also describe two techniques for preparing the crystals that are subsequently stacked.

In this work we describe a technique that is used to create new crystals (van der Waals heterostructures) by stacking ultrathin layered 2D materials with precise control over position and relative orientation.

In this work we describe a technique for creating new crystals (van der Waals heterostructures) by stacking distinct ultrathin layered 2D materials. We ...

Method Development for Contactless Resonant Cavity Dielectric Spectroscopic Studies of Cellulosic Paper

The current analytical techniques for characterizing printing and graphic arts substrates are largely ex situ and destructive. This limits the amount of data that can be obtained from an individual sample and renders it difficult to produce statistically relevant data for unique and rare materials. Resonant cavity dielectric spectroscopy is a non-destructive, contactless technique which can simultaneously interrogate both sides of a sheeted material and provide measurements which are suitable for statistical interpretations. This offers analysts the ability to quickly discriminate between sheeted materials based on composition and storage history. In this methodology article, we demonstrate how contactless resonant cavity dielectric spectroscopy may be used to differentiate between paper analytes of varying fiber species compositions, to determine the relative age of the paper, and to detect and quantify the amount of post-consumer waste (PCW) recycled fiber content in manufactured office paper.

A protocol for the non-destructive analysis of the fiber content and relative age of paper.

The current analytical techniques for characterizing printing and graphic arts substrates are largely ex situ and destructive. This limits the amount of ...