{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,15]],"date-time":"2026-01-15T12:44:23Z","timestamp":1768481063738,"version":"3.49.0"},"reference-count":37,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2018,9,19]],"date-time":"2018-09-19T00:00:00Z","timestamp":1537315200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["51573013"],"award-info":[{"award-number":["51573013"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>We demonstrate the fabrication of novel reduced graphene oxide (rGO)-based double network (DN) hydrogels through the polymerization of poly(N-isopropylacrylamide) (PNIPAm) and carboxymethyl chitosan (CMC). The facile synthesis of DN hydrogels includes the reduction of graphene oxide (GO) by CMC, and the subsequent polymerization of PNIPAm. The presence of rGO in the fabricated PNIPAm\/CMC\/rGO DN hydrogels enhances the compressibility and flexibility of hydrogels with respect to pure PNIPAm hydrogels, and they exhibit favorable thermoresponsivity, compressibility, and conductivity. The created hydrogels can be continuously cyclically compressed and have excellent bending properties. Furthermore, it was found that the hydrogels are pressure- and temperature-sensitive, and can be applied to the design of both pressure and temperature sensors to detect mechanical deformation and to measure temperature. Our preliminary results suggest that these rGO-based DN hydrogels exhibit a high potential for the fabrication of soft robotics and artificially intelligent skin-like devices.<\/jats:p>","DOI":"10.3390\/s18093162","type":"journal-article","created":{"date-parts":[[2018,9,19]],"date-time":"2018-09-19T10:50:31Z","timestamp":1537354231000},"page":"3162","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":26,"title":["Reduced Graphene Oxide-Based Double Network Polymeric Hydrogels for Pressure and Temperature Sensing"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9902-1797","authenticated-orcid":false,"given":"Wei","family":"Liu","sequence":"first","affiliation":[{"name":"State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China"},{"name":"Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing 100029, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaoyuan","family":"Zhang","sequence":"additional","affiliation":[{"name":"Otto Schott Institute of Materials Research, Friedrich-Schiller University Jena, 07743 Jena, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3838-8659","authenticated-orcid":false,"given":"Gang","family":"Wei","sequence":"additional","affiliation":[{"name":"Faculty of Production Engineering, University of Bremen, D-28359 Bremen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhiqiang","family":"Su","sequence":"additional","affiliation":[{"name":"State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China"},{"name":"Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, Beijing 100029, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2018,9,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1406","DOI":"10.1021\/bm100253e","article-title":"Design of renewable hydrogel release systems from fiberboard mill wastewater","volume":"11","author":"Albertsson","year":"2010","journal-title":"Biomacromolecules"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"4287","DOI":"10.1021\/ma070104v","article-title":"Gelation Mechanism of Poly(N-isopropylacrylamide)-Clay Nanocomposite Gels","volume":"40","author":"Miyazaki","year":"2007","journal-title":"Macromolecules"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"471","DOI":"10.1002\/adfm.201401989","article-title":"Dipole\u2013Dipole and H-Bonding Interactions Significantly Enhance the Multifaceted Mechanical Properties of Thermoresponsive Shape Memory Hydrogels","volume":"25","author":"Zhang","year":"2015","journal-title":"Adv. Funct. Mater."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"10017","DOI":"10.1021\/ma102044n","article-title":"Preparation and characterization of novel amphiphilic hydrogels with covalently attached drugs and fluorescent markers","volume":"43","author":"Lin","year":"2010","journal-title":"Macromolecules"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"310","DOI":"10.1021\/bm050663e","article-title":"Biodendrimer-based hydrogel scaffolds for cartilage tissue repair","volume":"7","author":"Nettles","year":"2006","journal-title":"Biomacromolecules"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"4453","DOI":"10.1021\/cr100123h","article-title":"Biopolymer-based hydrogels for cartilage tissue engineering","volume":"111","author":"Balakrishnan","year":"2011","journal-title":"Chem. Rev."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1098\/rspa.1967.0160","article-title":"The strength of highly elastic materials","volume":"300","author":"Lake","year":"1967","journal-title":"Proc. R. Soc. Lond. A"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1007","DOI":"10.1071\/CH11156","article-title":"Progress toward robust polymer hydrogels","volume":"64","author":"Naficy","year":"2011","journal-title":"Aust. J. Chem."},{"key":"ref_9","unstructured":"Fung, Y.C. (2013). Biomechanics: Mechanical Properties of Living Tissues, Springer. [2nd ed.]."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"637","DOI":"10.1002\/jor.1100120506","article-title":"Elastic modulus of calcified cartilage is an order of magnitude less than that of subchondral bone","volume":"12","author":"Mente","year":"1994","journal-title":"J. Orthop. Res."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1155","DOI":"10.1002\/adma.200304907","article-title":"Double-network hydrogels with extremely high mechanical strength","volume":"15","author":"Gong","year":"2003","journal-title":"Adv. Mater."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2583","DOI":"10.1039\/b924290b","article-title":"Why are double network hydrogels so tough?","volume":"6","author":"Gong","year":"2010","journal-title":"Soft Matter"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"8916","DOI":"10.1021\/ma201653t","article-title":"Lamellar bilayers as reversible sacrificial bonds to toughen hydrogel: Hysteresis, self-recovery, fatigue resistance, and crack blunting","volume":"44","author":"Haque","year":"2011","journal-title":"Macromolecules"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"7775","DOI":"10.1021\/ma2016248","article-title":"Microgel-reinforced hydrogel films with high mechanical strength and their visible mesoscale fracture structure","volume":"44","author":"Hu","year":"2011","journal-title":"Macromolecules"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1021\/mz3006318","article-title":"Double-network strategy improves fracture properties of chondroitin sulfate networks","volume":"2","author":"Suekama","year":"2013","journal-title":"ACS Macro Lett."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"3654","DOI":"10.1039\/C5TB00123D","article-title":"Fundamentals of double network hydrogels","volume":"3","author":"Chen","year":"2015","journal-title":"J. Mater. Chem. B"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1246","DOI":"10.1002\/polb.22293","article-title":"Effect of void structure on the toughness of double network hydrogels","volume":"49","author":"Nakajima","year":"2011","journal-title":"J. Polym. Sci. Part B Polym. Phys."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"5776","DOI":"10.1021\/ma200693e","article-title":"Structure and mechanism of strength enhancement in interpenetrating polymer network hydrogels","volume":"44","author":"Waters","year":"2011","journal-title":"Macromolecules"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"6034","DOI":"10.1039\/c3nr00214d","article-title":"An inorganic\u2013organic double network hydrogel of graphene and polymer","volume":"5","author":"Huang","year":"2013","journal-title":"Nanoscale"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"4309","DOI":"10.1039\/C7PY00935F","article-title":"Fabrication of Graphene\u2013Biomacromolecule Hybrid Materials for Tissue Engineering Application","volume":"8","author":"Li","year":"2017","journal-title":"Polym. Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"35338","DOI":"10.1039\/C5RA04164C","article-title":"Cuprous Oxide Microspheres on Graphene Nanosheets: An Enhanced Material for Non-Enzymatic Electrochemical Detection of H2O2 and Glucose","volume":"5","author":"Ding","year":"2015","journal-title":"RSC Adv."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"176","DOI":"10.1016\/j.cej.2017.10.148","article-title":"Gold Nanocluster Embedded Bovine Serum Albumin Nanofibers-Graphene Hybrid Membranes for the Efficient Detection and Separation of Mercury Ion","volume":"335","author":"Yu","year":"2018","journal-title":"Chem. Eng. J."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"42258","DOI":"10.1038\/srep42258","article-title":"Functionalized graphene oxide with chitosan for protein nanocarriers to protect against enzymatic cleavage and retain collagenase activity","volume":"7","author":"Emadi","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"812","DOI":"10.1016\/j.carbpol.2016.06.024","article-title":"Lactobionic acid and Carboxymethyl Chitosan Functionalized Graphene Oxide Nanocomposites as Targeted Anticancer Drug Delivery Systems","volume":"151","author":"Pan","year":"2016","journal-title":"Carbohydr. Polym."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"28842","DOI":"10.3390\/s151128842","article-title":"A Room-Temperature Operation Formaldehyde Sensing Material Printed Using Blends of Reduced Graphene Oxide and Poly(methyl methacrylate)","volume":"15","author":"Chuang","year":"2015","journal-title":"Sensors"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1016\/j.carbpol.2015.08.058","article-title":"Carboxymethyl Chitosan-Mediated Synthesis of hyaluronic Acid-Targeted Graphene Oxide for Cancer Drug Delivery","volume":"135","author":"Yang","year":"2016","journal-title":"Carbohydr. Polym."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"296","DOI":"10.1021\/sc400352a","article-title":"Supramolecular Hydrogel of Chitosan in the Presence of Graphene Oxide Nanosheets as 2D Cross-Linkers","volume":"2","author":"Han","year":"2013","journal-title":"ACS Sustain. Chem. Eng."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"4806","DOI":"10.1021\/nn1006368","article-title":"Improved Synthesis of Graphene Oxide","volume":"4","author":"Marcano","year":"2010","journal-title":"ACS Nano"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"13656","DOI":"10.1039\/C8RA01916A","article-title":"Partially reduced graphene oxide and chitosan nanohybrid membranes for selective retention of divalent cations","volume":"8","author":"Wei","year":"2018","journal-title":"RSC Adv."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"22470","DOI":"10.1039\/C4RA01718H","article-title":"Facile and green synthesis of graphene","volume":"4","author":"Vusa","year":"2014","journal-title":"RSC Adv."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"6525","DOI":"10.1039\/c3tb21270j","article-title":"One-pot Green Synthesis, Characterizations, and Biosensor Application of Self-Assembled Reduced Graphene Oxide-Gold Nanoparticle Hybrid Membranes","volume":"1","author":"Zhang","year":"2013","journal-title":"J. Mater. Chem. B"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"8980","DOI":"10.1021\/la5024086","article-title":"One-step Synthesis of Large-Scale Graphene Film Doped with Gold Nanoparticles at Liquid-Air Interface for Electrochemistry and Raman Detection Applications","volume":"30","author":"Zhang","year":"2014","journal-title":"Langmuir"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1219","DOI":"10.1002\/adfm.201404247","article-title":"Conductive \u201csmart\u201d hybrid hydrogels with PNIPAM and nanostructured conductive polymers","volume":"25","author":"Shi","year":"2015","journal-title":"Adv. Funct. Mater."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"842","DOI":"10.1016\/j.msec.2016.09.081","article-title":"Mechanical properties of PNIPAM based hydrogels: A review","volume":"70","author":"Haq","year":"2017","journal-title":"Mater. Sci. Eng. C"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"7852","DOI":"10.1021\/acsami.6b16690","article-title":"Thermosensitive ZrP-PNIPAM Pickering Emulsifier and the Controlled-Release Behavior","volume":"9","author":"Wang","year":"2017","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Yu, J., Lewis, E., Brambilla, G., and Wang, P. (2018). Temperature Sensing Performance of Microsphere Resonators. Sensors, 18.","DOI":"10.3390\/s18082515"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"17861","DOI":"10.1039\/C5NR04889C","article-title":"Nd3+-sensitized NaLuF4 luminescent nanoparticles for multimodal imaging and temperature sensing under 808 nm excitation","volume":"7","author":"Wang","year":"2015","journal-title":"Nanoscale"}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/9\/3162\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T15:21:27Z","timestamp":1760196087000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/18\/9\/3162"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2018,9,19]]},"references-count":37,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2018,9]]}},"alternative-id":["s18093162"],"URL":"https:\/\/doi.org\/10.3390\/s18093162","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2018,9,19]]}}}