Name: sensitivity enhancement of soft capacitive pressure sensors using a solvent evaporation-based porosity control technique
Uploaded: 2023-03-24T14:40:00
Description: Watch this Scientific Journal Video about Sensitivity Enhancement of Soft Capacitive Pressure Sensors Using a Solvent Evaporation-Based Porosity Control Technique at JoVE.com

This work was supported by the National Natural Science Foundation of China under Grant 62273304.

1. Fabrication of the soft capacitive pressure sensor with a porous PDMS dielectric layer
<ol>
	<li>Manufacturing of the porous PDMS dielectric layer
	<ol>
		<li>Prepare the sugar/erythritol porous template following the steps below.
		<ol>
			<li>Filter the sugar with sample sieves with apertures of 270 &#181;m and 500 &#181;m. Choose sugar with a particle diameter in the range of 270-500 &#181;m. 
			NOTE: A larger or smaller sugar particle size is also acceptable as long as the uniformity is wi...

<ol>
	<li>Ozioko, O., 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=SensAct:+The+soft+and+squishy+tactile+Sensor+with+integrated+flexible+actuator.">SensAct: The soft and squishy tactile Sensor with integrated flexible actuator.</a> Advanced Intelligent Systems. 3 (3), 1900145 (2021).</li><li>Qiu, 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=A+biomimetic+drosera+capensis+with+adaptive+decision-predation+behavior+based+on+multifunctional+sensing+and+fast+actuating+capability.">A biomimetic drosera capensis with adaptive decision-predation behavior based on multifunctional sensing and fast actuating capability.</a> Advanced Functional Materials. 32 (13), 2110296 (2021).</li><li>Ntagios, M., Nassar, H., Pullanchiyodan, A., Navaraj, W. T., Dahiya, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Robotic+hands+with+intrinsic+tactile+sensing+via+3D+printed+soft+pressure+sensors.">Robotic hands with intrinsic tactile sensing via 3D printed soft pressure sensors.</a> Advanced Intelligent Systems. 2 (6), 1900080 (2019).</li><li>Tang, Z., Jia, S., Zhou, C., Li, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+Printing+of+highly+sensitive+and+large-measurement-range+flexible+pressure+sensors+with+a+positive+piezoresistive+effect.">3D Printing of highly sensitive and large-measurement-range flexible pressure sensors with a positive piezoresistive effect.</a> ACS Applied Materials &amp; Interfaces. 12 (25), 28669-28680 (2020).</li><li>Dai, Y., Chen, J., Tian, W., Xu, L., Gao, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+PVDF/Au/PEN+multifunctional+flexible+human-machine+interface+for+multidimensional+sensing+and+energy+harvesting+for+the+internet+of+things.">A PVDF/Au/PEN multifunctional flexible human-machine interface for multidimensional sensing and energy harvesting for the internet of things.</a> IEEE Sensors Journal. 20 (14), 7556-7568 (2020).</li><li>Yang, 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=Flexible+piezoelectric+pressure+sensor+based+on+polydopamine-modified+BaTiO3/PVDF+composite+film+for+human+motion+monitoring.">Flexible piezoelectric pressure sensor based on polydopamine-modified BaTiO3/PVDF composite film for human motion monitoring.</a> Sensors and Actuators A: Physical. 301, 111789 (2020).</li><li>Gao, Y. 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=Wearable+microfluidic+diaphragm+pressure+sensor+for+health+and+tactile+touch+monitoring.">Wearable microfluidic diaphragm pressure sensor for health and tactile touch monitoring.</a> Advanced Materials. 29 (39), 1701985 (2017).</li><li>Meng, 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=Flexible+weaving+constructed+self-powered+pressure+sensor+enabling+continuous+diagnosis+of+cardiovascular+disease+and+measurement+of+cuffless+blood+pressure.">Flexible weaving constructed self-powered pressure sensor enabling continuous diagnosis of cardiovascular disease and measurement of cuffless blood pressure.</a> Advanced Functional Materials. 29 (5), 180688 (2019).</li><li>Yang, J. 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=Microstructured+porous+pyramid-based+ultrahigh+sensitive+pressure+sensor+insensitive+to+strain+and+temperature.">Microstructured porous pyramid-based ultrahigh sensitive pressure sensor insensitive to strain and temperature.</a> ACS Applied Materials &amp; Interfaces. 11 (21), 19472-19480 (2019).</li><li>Chen, S., Zhuo, B., Guo, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large+area+one-step+facile+processing+of+microstructured+elastomeric+dielectric+film+for+high+sensitivity+and+durable+sensing+over+wide+pressure+range.">Large area one-step facile processing of microstructured elastomeric dielectric film for high sensitivity and durable sensing over wide pressure range.</a> ACS Applied Materials &amp; Interfaces. 8 (31), 20364-20370 (2016).</li><li>Ding, 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=Influence+of+the+pore+size+on+the+sensitivity+of+flexible+and+wearable+pressure+sensors+based+on+porous+Ecoflex+dielectric+layers.">Influence of the pore size on the sensitivity of flexible and wearable pressure sensors based on porous Ecoflex dielectric layers.</a> Materials Research Express. 6 (6), 066304 (2019).</li><li>Yoon, J. I., Choi, K. S., Chang, S. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+means+of+fabricating+microporous+structures+for+the+dielectric+layers+of+capacitive+pressure+sensor.">A novel means of fabricating microporous structures for the dielectric layers of capacitive pressure sensor.</a> Microelectronic Engineering. 179, 60-66 (2017).</li><li>Wang, J., Li, L., Zhang, L., Zhang, P., Pu, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flexible+capacitive+pressure+sensors+with+micro-patterned+porous+dielectric+layer+for+wearable+electronics.">Flexible capacitive pressure sensors with micro-patterned porous dielectric layer for wearable electronics.</a> Journal of Micromechanics and Microengineering. 32 (3), 034003 (2022).</li><li>Mannsfeld, S. C. B., 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=Highly+sensitive+flexible+pressure+sensors+with+microstructured+rubber+dielectric+layers.">Highly sensitive flexible pressure sensors with microstructured rubber dielectric layers.</a> Nature Materials. 9 (10), 859-864 (2010).</li><li>Wan, 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=A+highly+sensitive+flexible+capacitive+tactile+sensor+with+sparse+and+high-aspect-ratio+microstructures.">A highly sensitive flexible capacitive tactile sensor with sparse and high-aspect-ratio microstructures.</a> Advanced Electronic Materials. 4 (4), 1700586 (2018).</li><li>Kwon, 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=Highly+sensitive,+flexible,+and+wearable+pressure+sensor+based+on+a+giant+piezocapacitive+effect+of+three-dimensional+microporous+elastomeric+dielectric+layer.">Highly sensitive, flexible, and wearable pressure sensor based on a giant piezocapacitive effect of three-dimensional microporous elastomeric dielectric layer.</a> ACS Applied Materials &amp; Interfaces. 8 (26), 16922-16931 (2016).</li><li>Li, W., 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=A+porous+and+air+gap+elastomeric+dielectric+layer+for+wearable+capacitive+pressure+sensor+with+high+sensitivity+and+a+wide+detection+range.">A porous and air gap elastomeric dielectric layer for wearable capacitive pressure sensor with high sensitivity and a wide detection range.</a> Journal of Materials Chemistry C. 8 (33), 11468-11476 (2020).</li><li>Kim, J. O., 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=Highly+ordered+3D+microstructure-based+electronic+skin+capable+of+differentiating+pressure,+temperature,+and+proximity.">Highly ordered 3D microstructure-based electronic skin capable of differentiating pressure, temperature, and proximity.</a> ACS Applied Materials &amp; Interfaces. 11 (1), 1503-1511 (2019).</li><li>Lo, L. W., 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=A+soft+sponge+sensor+for+multimodal+sensing+and+distinguishing+of+pressure,+strain,+and+temperature.">A soft sponge sensor for multimodal sensing and distinguishing of pressure, strain, and temperature.</a> ACS Applied Materials &amp; Interfaces. 14 (7), 9570-9578 (2022).</li><li>Hwang, J., Kim, Y., Yang, H., Oh, J. H. <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+hierarchically+porous+structured+PDMS+composites+and+their+application+as+a+flexible+capacitive+pressure+sensor.">Fabrication of hierarchically porous structured PDMS composites and their application as a flexible capacitive pressure sensor.</a> Composites Part B: Engineering. 211, 108607 (2021).</li><li>Jung, 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=Linearly+sensitive+pressure+sensor+based+on+a+porous+multistacked+composite+structure+with+controlled+mechanical+and+electrical+properties.">Linearly sensitive pressure sensor based on a porous multistacked composite structure with controlled mechanical and electrical properties.</a> ACS Applied Materials &amp; Interfaces. 13 (24), 28975-28984 (2021).</li><li>Choi, 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=Synergetic+effect+of+porous+elastomer+and+percolation+of+carbon+nanotube+filler+toward+high+performance+capacitive+pressure+sensors.">Synergetic effect of porous elastomer and percolation of carbon nanotube filler toward high performance capacitive pressure sensors.</a> ACS Applied Materials &amp; Interfaces. 12 (1), 1698-1706 (2020).</li><li>Choi, S. 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=A+polydimethylsiloxane+(PDMS)+sponge+for+the+selective+absorption+of+oil+from+water.">A polydimethylsiloxane (PDMS) sponge for the selective absorption of oil from water.</a> ACS Applied Materials &amp; Interfaces. 3 (12), 4552-4556 (2011).</li><li>Rinaldi, A., Tamburrano, A., Fortunato, M., Sarto, M. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+flexible+and+highly+sensitive+pressure+sensor+based+on+a+PDMS+foam+coated+with+graphene+nanoplatelets.">A flexible and highly sensitive pressure sensor based on a PDMS foam coated with graphene nanoplatelets.</a> Sensors. 16 (12), 2148 (2016).</li></ol>

This work proposes a simple method based on solvent evaporation to control the porosity, and a series of experimental results have proved its feasibility. Although the porous structure has been widely used in the flexible capacitive pressure sensor, the porosity control still needs further optimization. Unlike existing methods for changing the particle size of the PFA11,12,13,18,<sup...

In recent years, flexible pressure sensors have been drawing attention due to their indispensable application in soft robotics1,2,3, &#34;man-machine&#34; haptic interfaces4,5, and health monitoring6,7,8. Generally, the mechanisms for pressure sensing include piezoresistive1,4,7, piezoelectric2,6, capacitive2,3,9,10,11,12,13, and triboelectric8 sensors. Among them, capacitive pressure sensors stand out as one of the most promising methods in tactile sensing due to their high sensitivity, low limit of detection (LOD), etc.
For better sensing performance, various microstructures such as micro-pyramids2,9,14, micro-pillars15, and micro-pores9,10,11,12,13,16,17 have been introduced to flexible capacitive pressure sensors, and the fabrication methods have also been optimized to further improve the sensing performances of such structures. However, most of these structures require sophisticated microfabrication facilities, which significantly increases the manufacturing costs and operational difficulties. For example, as the most commonly used microstructure in soft pressure sensors, micro-pyramids rely on lithographically defined and wet-etched Si wafers as the molding template, which requires precision equipment and a strict cleanroom environment9,14. Therefore, micropore structures (porous structures) that can be made by simple fabrication processes and with low-cost raw materials while maintaining high sensing performances have drawn increasing attention recently9,10,11,12,13,16,17. This will be discussed, alongside the disadvantages of changing the PFA and its amount, as the motivation for using our fraction control method.
Herein, this work proposes a simple and low-cost method based on the solvent-evaporation technique to fabricate a porous flexible capacitive pressure sensor with controllable porosity. The complete manufacturing process includes the fabrication of the porous PDMS dielectric layer, the scrape coating of the electrodes, and the bonding of three functional layers. Specifically, this work innovatively uses a PDMS/toluene mixed solution with a certain mass ratio to fabricate the porous PDMS dielectric layer based on the sugar/erythritol mixture template. Meanwhile, a uniform PFA particle size ensures uniform pore morphology and distribution; thus, the porosity can be controlled by changing the PDMS/toluene mass ratio. The experimental results show that the sensitivity of the proposed pressure sensor can be enhanced more than two-fold by increasing the PDMS/toluene mass ratio from 1:8 to 1:1. The variation in the micropore wall thickness due to different PDMS/toluene mass ratios is also confirmed by optical microscope images. The optimized soft capacitive pressure sensor shows a high sensing performance with a sensitivity and response time of 3.47% kPa&#8722;1 and 0.2 s, respectively. This method achieves the fast, low-cost, and easy-operation fabrication of a porous dielectric layer with controllable porosity.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>3D printer</td>
			<td>Zhejiang Qidi Technology Co., Ltd</td>
			<td>X-MAX</td>
			<td></td>
		</tr>
		<tr>
			<td>3D printing metarials</td>
			<td>Zhejiang Qidi Technology Co., Ltd</td>
			<td>3D Printing Filament PLA 1.75 mm</td>
			<td></td>
		</tr>
		<tr>
			<td>Carbon nanotubes (CNTs)</td>
			<td>XFNANO</td>
			<td>XFM13</td>
			<td></td>
		</tr>
		<tr>
			<td>Data acquisition (DAQ)</td>
			<td>National Instruments</td>
			<td>USB6002</td>
			<td></td>
		</tr>
		<tr>
			<td>Double side tape</td>
			<td>Minnesota Mining and Manufacturing (3M)</td>
			<td>3M VHB 4910</td>
			<td>1 mm thick</td>
		</tr>
		<tr>
			<td>Electrode metal mold</td>
			<td>Guangdong Shunde Molarobot Co., Ltd</td>
			<td></td>
			<td>This metal mold is a round metal plate with a flat bottom round groove and an embossed electrode pattern of 0.2 mm thick in the middle of the groove.</td>
		</tr>
		<tr>
			<td>Erythritol</td>
			<td>Shandong Sanyuan Biotechnology Co.,Ltd.</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Isopropyl Alcohol (IPA)</td>
			<td>Sinopharm chemical reagent Co., Ltd</td>
			<td>80109218</td>
			<td></td>
		</tr>
		<tr>
			<td>LabVIEW</td>
			<td>National Instruments</td>
			<td>LabVIEW 2019</td>
			<td></td>
		</tr>
		<tr>
			<td>LCR meter</td>
			<td>Keysight</td>
			<td>EA4980AL</td>
			<td></td>
		</tr>
		<tr>
			<td>Metal wire</td>
			<td>Hangzhou Hongtong WIRE&#38;CABLE Co., Ltd.</td>
			<td>2UEW/155</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope</td>
			<td>Aosvi</td>
			<td>T2-3M180</td>
			<td></td>
		</tr>
		<tr>
			<td>Numerical modeling software</td>
			<td>COMSOL</td>
			<td>COMSOL Multiphysics 5.6</td>
			<td></td>
		</tr>
		<tr>
			<td>Polydimethylsiloxane (PDMS)</td>
			<td>Dow Chemical Company</td>
			<td>SYLGAR 184 Silicone Elastomer Kit</td>
			<td>Two parts (base and curing agent)</td>
		</tr>
		<tr>
			<td>Sealing film</td>
			<td>Corning</td>
			<td>PM-996</td>
			<td>parafilm</td>
		</tr>
		<tr>
			<td>Si wafer</td>
			<td>Suzhou Crystal Silicon Electronic &#38; Technology Co.,Ltd</td>
			<td>ZK20220416-03</td>
			<td>Diameter (mm): 50.8 +/- 0.3 
			Type/Orientation: P/100 
			Thickness (&#181;m): 525 +/- 25</td>
		</tr>
		<tr>
			<td>Silver conductive paint</td>
			<td>Electron Microscopy Sciences</td>
			<td>12686-15</td>
			<td></td>
		</tr>
		<tr>
			<td>Stepping motor</td>
			<td>BEIJING HAI JIE JIA CHUANG Technology Co., Ltd</td>
			<td>57H B56L4-30DB</td>
			<td></td>
		</tr>
		<tr>
			<td>Sugar/erythritol template metal mold</td>
			<td>Guangdong Shunde Molarobot Co., Ltd</td>
			<td></td>
			<td>This metal mold is a 5 mm thick square metal plate with a flat bottom square groove of 2.5 mm deep.</td>
		</tr>
		<tr>
			<td>Toluene</td>
			<td>Sinopharm chemical reagent Co., Ltd</td>
			<td>10022819</td>
			<td></td>
		</tr>
	</tbody>
</table>

sensitivity enhancement of soft capacitive pressure sensors using a solvent evaporation-based porosity control technique

Soft pressure sensors play a significant role in developing &#34;man-machine&#34; tactile sensation in soft robotics and haptic interfaces. Specifically, capacitive sensors with micro-structured polymer matrices have been explored with considerable effort because of their high sensitivity, wide linearity range, and fast response time. However, the improvement of the sensing performance often relies on the structural design of the dielectric layer, which requires sophisticated microfabrication facilities. This article reports a simple and low-cost method to fabricate porous capacitive pressure sensors with improved sensitivity using the solvent evaporation-based method to tune the porosity. The sensor consists of a porous polydimethylsiloxane (PDMS) dielectric layer bonded with top and bottom electrodes made of elastic conductive polymer composites (ECPCs). The electrodes were prepared by scrape-coating carbon nanotubes (CNTs)-doped PDMS conductive slurry into mold-patterned PDMS films. To optimize the porosity of the dielectric layer for enhanced sensing performance, the PDMS solution was diluted with toluene of different mass fractions instead of filtering or grinding the sugar pore-forming agent (PFA) into different sizes. The evaporation of the toluene solvent allowed the fast fabrication of a porous dielectric layer with controllable porosities. It was confirmed that the sensitivity could be enhanced more two-fold when the toluene to PDMS ratio was increased from 1:8 to 1:1. The research proposed in this work enables a low-cost method of fabricating fully integrated bionic soft robotic grippers with soft sensory mechanoreceptors of tunable sensor parameters.

The photograph of the lumped sugar/erythritol porous template is shown in Figure 3A. Figure 3B shows the flexible electrode layer with a scrape-coated ECPCs pattern. Figure 3C shows the soft capacitive pressure sensor with a porous dielectric layer fabricated with the proposed method. Four porous PDMS dielectric layers were fabricated based on PDMS/toluene solutions with different mass ratios of 1:1, 3:1, 5:1, and 8...

Watch this Scientific Journal Video about Sensitivity Enhancement of Soft Capacitive Pressure Sensors Using a Solvent Evaporation-Based Porosity Control Technique at JoVE.com

Sensitivity Enhancement of Soft Capacitive Pressure Sensors Using a Solvent Evaporation-Based Porosity Control Technique

A simple and cost-efficient fabrication method based on the solvent evaporation technique is presented to optimize the performance of a soft capacitive pressure sensor, which is enabled by porosity control in the dielectric layer using different mass ratios of the molding PDMS/toluene solution.

Soft pressure sensors play a significant role in developing &#34;man-machine&#34; tactile sensation in soft robotics and haptic interfaces. Specifically, ...

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