Hydraulic Hydrogel Actuators and Robots Optically and Sonically Camouflaged in Water

Overview

Journal Nat Commun

Specialty Biology

Date 2017 Feb 2

PMID 28145412

Citations 113

Authors

Hyunwoo Yuk

Shaoting Lin

Chu Ma

Mahdi Takaffoli

Nicolas X Fang

Xuanhe Zhao

Affiliations

Soon will be listed here.

Abstract

Sea animals such as leptocephali develop tissues and organs composed of active transparent hydrogels to achieve agile motions and natural camouflage in water. Hydrogel-based actuators that can imitate the capabilities of leptocephali will enable new applications in diverse fields. However, existing hydrogel actuators, mostly osmotic-driven, are intrinsically low-speed and/or low-force; and their camouflage capabilities have not been explored. Here we show that hydraulic actuations of hydrogels with designed structures and properties can give soft actuators and robots that are high-speed, high-force, and optically and sonically camouflaged in water. The hydrogel actuators and robots can maintain their robustness and functionality over multiple cycles of actuations, owing to the anti-fatigue property of the hydrogel under moderate stresses. We further demonstrate that the agile and transparent hydrogel actuators and robots perform extraordinary functions including swimming, kicking rubber-balls and even catching a live fish in water.

Citing Articles

Human camouflage and expression via soft mask from reprogrammable chemical fluid skin.

Zhong Y, Tang W, Gui H, Sheng Q, Xu H, Qin K Sci Adv. 2025; 11(7):eadq6141.

PMID: 39937920 PMC: 11818024. DOI: 10.1126/sciadv.adq6141.

Monolithic electrostatic actuators with independent stiffness modulation.

Xu Y, Wen J, Burdet E, Taghavi M Nat Commun. 2025; 16(1):1174.

PMID: 39885138 PMC: 11782490. DOI: 10.1038/s41467-025-56455-z.

Development and Applications in Intelligent Sports of Hydrogel-Based Triboelectric Nanogenerators.

Feng G, Wang Y, Liu D, Cheng Z, Feng Q, Wang H Materials (Basel). 2025; 18(1.

PMID: 39795679 PMC: 11721276. DOI: 10.3390/ma18010033.

The Dynamic Mortise-and-Tenon Interlock Assists Hydrated Soft Robots Toward Off-Road Locomotion.

Wu B, Xue Y, Ali I, Lu H, Yang Y, Yang X Research (Wash D C). 2024; 2022:0015.

PMID: 39290972 PMC: 11407522. DOI: 10.34133/research.0015.

Hydrogels in Soft Robotics: Past, Present, and Future.

Lopez-Diaz A, Vazquez A, Vazquez E ACS Nano. 2024; 18(32):20817-20826.

PMID: 39099317 PMC: 11328171. DOI: 10.1021/acsnano.3c12200.

References

Lin S, Yuk H, Zhang T, Parada G, Koo H, Yu C . Stretchable Hydrogel Electronics and Devices. Adv Mater. 2015; 28(22):4497-505. PMC: 4896855. DOI: 10.1002/adma.201504152. View

Kim Y, Liu M, Ishida Y, Ebina Y, Osada M, Sasaki T . Thermoresponsive actuation enabled by permittivity switching in an electrostatically anisotropic hydrogel. Nat Mater. 2015; 14(10):1002-7. DOI: 10.1038/nmat4363. View

Palleau E, Morales D, Dickey M, Velev O . Reversible patterning and actuation of hydrogels by electrically assisted ionoprinting. Nat Commun. 2013; 4:2257. DOI: 10.1038/ncomms3257. View

Bauer S, Bauer-Gogonea S, Graz I, Kaltenbrunner M, Keplinger C, Schwodiauer R . 25th anniversary article: A soft future: from robots and sensor skin to energy harvesters. Adv Mater. 2013; 26(1):149-61. PMC: 4240516. DOI: 10.1002/adma.201303349. View

Johnsen S . Hidden in plain sight: the ecology and physiology of organismal transparency. Biol Bull. 2001; 201(3):301-18. DOI: 10.2307/1543609. View

Wang Q, Gossweiler G, Craig S, Zhao X . Cephalopod-inspired design of electro-mechano-chemically responsive elastomers for on-demand fluorescent patterning. Nat Commun. 2014; 5:4899. DOI: 10.1038/ncomms5899. View

Keplinger C, Sun J, Foo C, Rothemund P, Whitesides G, Suo Z . Stretchable, transparent, ionic conductors. Science. 2013; 341(6149):984-7. DOI: 10.1126/science.1240228. View

Morin S, Shepherd R, Kwok S, Stokes A, Nemiroski A, Whitesides G . Camouflage and display for soft machines. Science. 2012; 337(6096):828-32. DOI: 10.1126/science.1222149. View

Dong L, Agarwal A, Beebe D, Jiang H . Adaptive liquid microlenses activated by stimuli-responsive hydrogels. Nature. 2006; 442(7102):551-4. DOI: 10.1038/nature05024. View

10.

Beebe , Moore , BAUER , Yu , Liu , Devadoss . Functional hydrogel structures for autonomous flow control inside microfluidic channels. Nature. 2000; 404(6778):588-90. DOI: 10.1038/35007047. View

11.

Zell K, Sperl J, Vogel M, Niessner R, Haisch C . Acoustical properties of selected tissue phantom materials for ultrasound imaging. Phys Med Biol. 2007; 52(20):N475-84. DOI: 10.1088/0031-9155/52/20/N02. View

12.

Shepherd R, Ilievski F, Choi W, Morin S, Stokes A, Mazzeo A . Multigait soft robot. Proc Natl Acad Sci U S A. 2011; 108(51):20400-3. PMC: 3251082. DOI: 10.1073/pnas.1116564108. View

13.

Yuk H, Zhang T, Parada G, Liu X, Zhao X . Skin-inspired hydrogel-elastomer hybrids with robust interfaces and functional microstructures. Nat Commun. 2016; 7:12028. PMC: 4931236. DOI: 10.1038/ncomms12028. View

14.

Lee K, Mooney D . Hydrogels for tissue engineering. Chem Rev. 2001; 101(7):1869-79. DOI: 10.1021/cr000108x. View

15.

Yu C, Li Y, Zhang X, Huang X, Malyarchuk V, Wang S . Adaptive optoelectronic camouflage systems with designs inspired by cephalopod skins. Proc Natl Acad Sci U S A. 2014; 111(36):12998-3003. PMC: 4246966. DOI: 10.1073/pnas.1410494111. View

16.

Larson C, Peele B, Li S, Robinson S, Totaro M, Beccai L . Highly stretchable electroluminescent skin for optical signaling and tactile sensing. Science. 2016; 351(6277):1071-4. DOI: 10.1126/science.aac5082. View

17.

Sidorenko A, Krupenkin T, Taylor A, Fratzl P, Aizenberg J . Reversible switching of hydrogel-actuated nanostructures into complex micropatterns. Science. 2007; 315(5811):487-90. DOI: 10.1126/science.1135516. View

18.

Yuk H, Zhang T, Lin S, Parada G, Zhao X . Tough bonding of hydrogels to diverse non-porous surfaces. Nat Mater. 2015; 15(2):190-6. PMC: 4762474. DOI: 10.1038/nmat4463. View

19.

Rus D, Tolley M . Design, fabrication and control of soft robots. Nature. 2015; 521(7553):467-75. DOI: 10.1038/nature14543. View

20.

Feinberg A, Feigel A, Shevkoplyas S, Sheehy S, Whitesides G, Parker K . Muscular thin films for building actuators and powering devices. Science. 2007; 317(5843):1366-70. DOI: 10.1126/science.1146885. View