Name: four-dimensional printing of stimuli-responsive hydrogel-based soft robots
Uploaded: 2023-01-13T13:10:00
Description: Watch this Scientific Journal Video about Four-Dimensional Printing of Stimuli-Responsive Hydrogel-Based Soft Robots at JoVE.com

The authors gratefully acknowledge support from the&#160;National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No.2022R1F1A1074266).

The stimuli-responsive soft gripper was composed of three different types of hydrogels: non-stimuli-responsive acrylamide (AAm)-based hydrogel, thermally responsive N-isopropyl acrylamide (NIPAM)-based hydrogel, and magnetic responsive ferrogel (Figure 1). The three hydrogel inks were prepared by modifying previously published methods29,30,31. The data presented in this study are available ...

<ol>
	<li>Gracias, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stimuli+responsive+self-folding+using+thin+polymer+films.">Stimuli responsive self-folding using thin polymer films.</a> Current Opinion in Chemical Engineering. 2 (1), 112-119 (2013).</li><li>Zhang, Y. S., Khademhosseini, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+engineering+hydrogels.">Advances in engineering hydrogels.</a> Science. 356 (6337), (2017).</li><li>Erol, O., Pantula, A., Liu, W., Gracias, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transformer+hydrogels:+A+review.">Transformer hydrogels: A review.</a> Advanced Materials Technologies. 4 (4), 1900043 (2019).</li><li>Liu, X., Liu, J., Lin, S., Zhao, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydrogel+machines.">Hydrogel machines.</a> Materials Today. 36, 102-124 (2020).</li><li>Hu, Z., Zhang, X., Li, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+and+application+of+modulated+polymer+gels.">Synthesis and application of modulated polymer gels.</a> Science. 269 (5223), 525-527 (1995).</li><li>Klein, Y., Efrati, E., Sharon, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shaping+of+elastic+sheets+by+prescription+of+non-Euclidean+metrics.">Shaping of elastic sheets by prescription of non-Euclidean metrics.</a> Science. 315 (5815), 1116-1120 (2007).</li><li>Kim, J., Hanna, J. A., Byun, M., Santangelo, C. D., Hayward, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Design+responsive+buckled+surfaces+by+halftone+gel+lithography.">Design responsive buckled surfaces by halftone gel lithography.</a> Science. 335 (6073), 1201-1205 (2012).</li><li>Breger, 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=Self-folding+thermo-magnetically+responsive+soft+microgrippers.">Self-folding thermo-magnetically responsive soft microgrippers.</a> ACS Applied Materials &amp; Interfaces. 7 (5), 3398-3405 (2015).</li><li>Schild, H. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Poly+(N-isopropylacrylamide):+Experiment,+theory+and+application.">Poly (N-isopropylacrylamide): Experiment, theory and application.</a> Progress in Polymer Science. 17 (2), 163-249 (1992).</li><li>Ahn, S., Kasi, R. M., Kim, S. -. C., Sharma, N., Zhou, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stimuli-responsive+polymer+gels.">Stimuli-responsive polymer gels.</a> Soft Matter. 4, 1151-1157 (2008).</li><li>Stuart, M. A., 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=Emerging+applications+of+stimuli-responsive+polymer+materials.">Emerging applications of stimuli-responsive polymer materials.</a> Nature Materials. 9, 101-113 (2010).</li><li>Ionov, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomimetic+hydrogel-based+actuating+systems.">Biomimetic hydrogel-based actuating systems.</a> Advanced Functional Materials. 23 (36), 4555-4570 (2013).</li><li>Ghosh, A., 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=Stimuli-responsive+soft+untethered+grippers+for+drug+delivery+and+robotic+surgery.">Stimuli-responsive soft untethered grippers for drug delivery and robotic surgery.</a> Frontiers in Mechanical Engineering. 3, 7 (2017).</li><li>Kirillova, A., Ionov, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Shape-changing+polymers+for+biomedical+applications.">Shape-changing polymers for biomedical applications.</a> Journal of Materials Chemistry B. 7, 1597-1624 (2019).</li><li>Le, X., Lu, W., Zhang, J., Chen, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+progress+in+biomimetic+anisotropic+hydrogel+actuators.">Recent progress in biomimetic anisotropic hydrogel actuators.</a> Advanced Science. 6 (5), 1801584 (2019).</li><li>Xu, W., Gracias, D. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Soft+three-dimensional+robots+with+hard+two-dimensional+materials.">Soft three-dimensional robots with hard two-dimensional materials.</a> ACS Nano. 13 (5), 4883-4892 (2019).</li><li>Yoon, C. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+biomimetic+stimuli+responsive+soft+grippers.">Advances in biomimetic stimuli responsive soft grippers.</a> Nano Convergence. 6, 20 (2019).</li><li>Lee, Y., Song, W. J., Sun, J. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hydrogel+soft+robotics.">Hydrogel soft robotics.</a> Materials Today Physics. 15, 100258 (2020).</li><li>Shen, Z., Chen, F., Zhu, X., Yong, K. T., Gu, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stimuli-responsive+functional+materials+for+soft+robotics.">Stimuli-responsive functional materials for soft robotics.</a> Journal of Materials Chemistry B. 8, 8972-8991 (2020).</li><li>Kim, 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=Shape+morphing+smart+3D+actuator+materials+for+micro+soft+robot.">Shape morphing smart 3D actuator materials for micro soft robot.</a> Materials Today. 41, 243-269 (2020).</li><li>Ding, M., 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=Multifunctional+soft+machines+based+on+stimuli-responsive+hydrogels:+From+freestanding+hydrogels+to+smart+integrated+systems.">Multifunctional soft machines based on stimuli-responsive hydrogels: From freestanding hydrogels to smart integrated systems.</a> Materials Today Advances. 8, 100088 (2020).</li><li>Wang, X., Jiang, M., Zhou, Z., Gou, J., Hui, D. <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+polymer+matrix+composites:+A+review+and+prospective.">3D printing of polymer matrix composites: A review and prospective.</a> Composites Part B: Engineering. 110, 442-458 (2017).</li><li>Bartlett, N. 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+3D-printed,+functionally+graded+soft+robot+powered+by+combustion.">A 3D-printed, functionally graded soft robot powered by combustion.</a> Science. 349 (6244), 161-165 (2015).</li><li>Wehner, M., 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=An+integrated+design+and+fabrication+strategy+for+entirely+soft,+autonomous+robots.">An integrated design and fabrication strategy for entirely soft, autonomous robots.</a> Nature. 536, 451-455 (2016).</li><li>Tibbits, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=4D+printing:+Multi-material+shape+change.">4D printing: Multi-material shape change.</a> Architectural Design. 84 (1), 116-121 (2014).</li><li>Gladman, A. S., Matsumoto, E. A., Nuzzo, R. G., Mahadevan, L., Lewis, J. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomimetic+4D+printing.">Biomimetic 4D printing.</a> Nature Materials. 15, 413-418 (2016).</li><li>Momeni, F., Hassani, S. M., Liu, X., Ni, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+review+of+4D+printing.">A review of 4D printing.</a> Materials &amp; Design. 125, 42-79 (2017).</li><li>Ionov, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=4D+biofabrication:+Materials,+methods,+and+applications.">4D biofabrication: Materials, methods, and applications.</a> Advanced Healthcare Materials. 7 (17), 1800412 (2018).</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=Dual-gel+4D+printing+of+bioinspired+tubes.">Dual-gel 4D printing of bioinspired tubes.</a> ACS Applied Materials &amp; Interfaces. 11 (8), 8492-8498 (2019).</li><li>Son, 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=Untethered+actuation+of+hybrid+hydrogel+gripper+via+ultrasound.">Untethered actuation of hybrid hydrogel gripper via ultrasound.</a> ACS Macro Letters. 9 (12), 1766-1772 (2020).</li><li>Ding, Z., Salim, A., Ziaie, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Squeeze-film+hydrogel+deposition+and+dry+micropatterning.">Squeeze-film hydrogel deposition and dry micropatterning.</a> Analytical Chemistry. 82 (8), 3377-3382 (2010).</li><li>Ongaro, F., 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=Autonomous+planning+and+control+of+soft+untethered+grippers+in+unstructured+environments.">Autonomous planning and control of soft untethered grippers in unstructured environments.</a> Journal of Micro-Bio Robotics. 12, 45-52 (2017).</li><li>Scheggi, S., 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=Magnetic+motion+control+and+planning+of+untethered+soft+grippers+using+ultrasound+image+feedback.">Magnetic motion control and planning of untethered soft grippers using ultrasound image feedback.</a> 2017 IEEE International Conference on Robotics and Automation (ICRA). IEEE. , 6156-6161 (2017).</li></ol>

In terms of material selection for the soft hybrid gripper, a multi-responsive material system composed of a non-stimuli-responsive AAm-based hydrogel, a thermally responsive NIPAM-based hydrogel, and a magnetic-responsive ferrogel was first prepared to allow the soft hybrid gripper to exhibit programmable locomotion and shape transformation. Owing to their thermally responsive swelling-deswelling properties, NIPAM-based hydrogels exhibit bending, folding, or wrinkling when fabricated as bilayer or bi-strip structures wi...

The development of stimuli-responsive soft robots is important from both technical and intellectual perspectives. The term stimuli-responsive soft robots generally refers to devices/systems composed of hydrogels, polymers, elastomers, or hybrids that exhibit shape changes in response to external cues, such as heat, pH, and light1,2,3,4. Among the many stimuli-responsive soft robots, N-isopropylacrylamide (NIPAM) hydrogel-based soft robots perform the desired tasks or interactions using spontaneous shape transformation5,6,7,8. Generally, the NIPAM-based hydrogels exhibit a low critical solution temperature (LCST), and swelling (hydrophilicity below the LCST) and deswelling (hydrophobicity above the LCST) property changes occur inside the hydrogel system near physiological temperatures between 32 &#176;C and 36 &#176;C9,10. This reversible swelling-deswelling mechanism near the sharp critical transition point of the LCST can generate the shape transformation of NIPAM-based hydrogel soft robots2. As a result, thermally responsive NIPAM-based hydrogel soft robots have improved operations, such as walking, gripping, crawling, and sensing, which are important in multifunctional manipulators, healthcare systems, and smart sensors2,3,4,11,12,13,14,15,16,17,18,19,20,21.
In the fabrication of stimuli-responsive soft robots, three-dimensional (3D) printing approaches have been widely employed using a direct layer-by-layer additive process22. A variety of materials, such as plastics and soft hydrogels, can be printed with 3D printing23,24. Recently, 4D printing has been extensively highlighted as an innovative technique for creating shape-programmable soft robots25,26,27,28. This 4D printing is based on 3D printing, and the key characteristic of 4D printing is that the 3D structures can change their shapes and properties over time.&#160;The combination of 4D printing and stimuli-responsive hydrogels has provided another innovative route to create smart 3D devices that change shape over time when exposed to appropriate external stimulus triggers, such as heat, pH, light, and magnetic and electric fields25,26,27,28. The development of this 4D printing technique using diverse stimuli-responsive hydrogels has provided an opportunity for the emergence of shape-transformable soft robots that display multifunctionality with improved response speeds and feedback sensitivity.
This study describes the creation of a 3D printing-driven thermally responsive soft gripper that displays shape transformation and locomotion. Notably, the specific procedure described can be utilized to fabricate various multifunctional soft robots with overall sizes ranging from the millimeter to centimeter length scales. Finally, it is expected that this protocol can be applied in several fields, including soft robots (e.g., smart actuators and locomotion robots), flexible electronics (e.g., optoelectrical sensors and lab-on-a-chip), and healthcare systems (e.g., drug delivery capsules, biopsy tools, and surgical devices).

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			<td>2-Hydroxy-4&#39;-(2-hydroxyethoxy)-2-methylpropiophenone</td>
			<td>Sigma Aldrich</td>
			<td>410896-50G</td>
			<td>Irgacure 2959, photoinitiator</td>
		</tr>
		<tr>
			<td>3D WOX 2X</td>
			<td>sindoh</td>
			<td>n/a</td>
			<td>3D printer for fabricating a maze</td>
		</tr>
		<tr>
			<td>Acrylamide</td>
			<td>Sigma-Aldrich</td>
			<td>29-007</td>
			<td>&#8805;99%</td>
		</tr>
		<tr>
			<td>Airbrush compressor</td>
			<td>WilTec</td>
			<td>AF18-2</td>
			<td></td>
		</tr>
		<tr>
			<td>Ammonium persulfate</td>
			<td>Sigma Aldrich</td>
			<td>A4418</td>
			<td></td>
		</tr>
		<tr>
			<td>Auto CAD</td>
			<td>Autodesk</td>
			<td>n/a</td>
			<td>software for computer-aided-design file</td>
		</tr>
		<tr>
			<td>BLX UV crosslinker</td>
			<td>BIO-LINK</td>
			<td>U01-133-565</td>
			<td></td>
		</tr>
		<tr>
			<td>Cartridge</td>
			<td>CELLINK</td>
			<td>CSC010300102</td>
			<td></td>
		</tr>
		<tr>
			<td>Digital stirring Hot Plates</td>
			<td>Corning</td>
			<td>6798-420D</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorescein O-methacrylate</td>
			<td>Sigma Aldrich</td>
			<td>568864</td>
			<td>dye of AAm gel</td>
		</tr>
		<tr>
			<td>INKREDIBLE+ bioprinter</td>
			<td>CELLINK</td>
			<td>n/a</td>
			<td></td>
		</tr>
		<tr>
			<td>Iron(III) Oxide red</td>
			<td>DUKSAN general science</td>
			<td>I0231</td>
			<td></td>
		</tr>
		<tr>
			<td>Laponite RD</td>
			<td>BYK</td>
			<td>n/a</td>
			<td>nanoclay</td>
		</tr>
		<tr>
			<td>Microcentrifuge tube</td>
			<td>SPL</td>
			<td>60615</td>
			<td></td>
		</tr>
		<tr>
			<td>Micro stirrer bar</td>
			<td>Cowie</td>
			<td>27-00360-08</td>
			<td>&#934;3&#215;<img alt="Equation 1" src="/files/ftp_upload/64870/64870img01.png" />0&#160;</td>
		</tr>
		<tr>
			<td>N, N, N&#39;, N&#39;-tetramethylethylenediamine</td>
			<td>Sigma Aldrich</td>
			<td>T7024-100ML</td>
			<td></td>
		</tr>
		<tr>
			<td>N, N&#39;-methylenebisacrylamide</td>
			<td>Sigma Aldrich</td>
			<td>M7279</td>
			<td>&#8805;99.5%</td>
		</tr>
		<tr>
			<td>N-isopropylacrylamide</td>
			<td>Sigma-Aldrich</td>
			<td>415324-50G</td>
			<td></td>
		</tr>
		<tr>
			<td>Poly(N-isopropylacrylamide)</td>
			<td>Sigma-Aldrich</td>
			<td>535311</td>
			<td></td>
		</tr>
		<tr>
			<td>Rhodamine 6G</td>
			<td>Sigma Aldrich</td>
			<td>R4127</td>
			<td>dye of NIPAM gel</td>
		</tr>
		<tr>
			<td>Slic3r software (v1.2.9)</td>
			<td>Slic3r</td>
			<td>n/a</td>
			<td>open-source software to convert .stl file to gcode</td>
		</tr>
		<tr>
			<td>Sodium hydroxide beads</td>
			<td>Sigma Aldrich</td>
			<td>S5881</td>
			<td></td>
		</tr>
		<tr>
			<td>Sterile high-precision conical bioprinting nozzles</td>
			<td>CELLINK</td>
			<td>NZ3270005001</td>
			<td>22 G, 25 G</td>
		</tr>
		<tr>
			<td>Syringe</td>
			<td>Korea vaccine</td>
			<td>K07415389</td>
			<td>10 CC 21 G (1-1/4 INCH)</td>
		</tr>
		<tr>
			<td>Vortex mixer</td>
			<td>DAIHAN</td>
			<td>DH.WVM00030</td>
			<td></td>
		</tr>
	</tbody>
</table>

four-dimensional printing of stimuli-responsive hydrogel-based soft robots

The present protocol describes the creation of four-dimensional (4D), time-dependent, shape-changeable, stimuli-responsive soft robots using a three-dimensional (3D) bio-printing method. Recently, 4D printing techniques have been extensively proposed as innovative new methods for developing shape-transformable soft robots. In particular, 4D time-dependent shape transformation is an essential factor in soft robotics because it allows effective functions to occur at the right time and place when triggered by external cues, such as heat, pH, and light. In line with this perspective, stimuli-responsive materials, including hydrogels, polymers, and hybrids, can be printed to realize smart shape-transformable soft robotic systems. The current protocol can be used to fabricate thermally responsive soft grippers composed of N-isopropylacrylamide (NIPAM)-based hydrogels, with overall sizes ranging from millimeters to centimeters in length. It is expected that this study will provide new directions for realizing intelligent soft robotic systems for various applications in smart manipulators (e.g., grippers, actuators, and pick-and-place machines), healthcare systems (e.g., drug capsules, biopsy tools, and microsurgeries), and electronics (e.g., wearable sensors and fluidics).

The NIPAM-based hydrogel was primarily considered when designing the thermally responsive soft gripper owing to its sharp LCST, which causes it to exhibit significant swelling-deswelling properties9,10. In addition, the AAm-based hydrogel was considered as a non-stimuli-responsive system to maximize the shape transformation of the soft hybrid gripper while reducing the delamination of the interface during multiple heating and cooling processes. In addition, ferro...

Watch this Scientific Journal Video about Four-Dimensional Printing of Stimuli-Responsive Hydrogel-Based Soft Robots at JoVE.com

Four-Dimensional Printing of Stimuli-Responsive Hydrogel-Based Soft Robots

This manuscript describes a 4D printing strategy for fabricating intelligent stimuli-responsive soft robots. This approach can provide the groundwork to facilitate the realization of intelligent shape-transformable soft robotic systems, including smart manipulators, electronics, and healthcare systems.

The present protocol describes the creation of four-dimensional (4D), time-dependent, shape-changeable, stimuli-responsive soft robots using a ...

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