Journal of Materials Science

, Volume 53, Issue 9, pp 6574–6585 | Cite as

Thermo-compression-aligned functional graphene showing anisotropic response to in-plane stretching and out-of-plane bending



Flexible and wearable sensors with high sensitivity are being expected for high-precision detection of subtle motions in human joints. In this study, we develop a graphene-based elastomer with tunable dielectric properties, which was further employed to construct a flexible capacitive sensor with highly anisotropic responses to the out-of-plane bending and in-plane stretching. To fabricate such a sensor, functional graphene derivatives are uniformly dispersed in a thermoplastic polyurethane (TPU) matrix and then aligned by a thermo-compression process. The uniform dispersion enables to elevate dielectric performance in composites leading to a high relative permittivity value of 97.3. In addition, adjacent graphene flakes are parallel to the hot plates due to the thermo-compression-induced alignment, thus behaving as microcapacitors to contribute to the sensitivity enhancement in the resulting sensors. Particularly, such sensors exhibit a sensitive response to the out-of-plane bending (30–180o), but are insensitive to the in-plane stretching (0–40 N). We further demonstrate that this sensor has a potential application in the field of virtual typing output.



We thank Dr. Su Shimei for support with dielectric measuring, and we gratefully acknowledge the financial support from the key research project plan of Higher Learning Institutions of Henan Province (17B430008), the National Natural Science Foundation of China (51573169 and 61704155) and the Startup Research Fund for Young teachers of Zhengzhou University (F0000907 and F0000992).

Supplementary material

10853_2018_2021_MOESM1_ESM.doc (13.5 mb)
Supplementary material 1 (DOC 13867 kb)


  1. 1.
    Yamada T, Hayamizu Y, Yamamoto Y, Yomogida Y, Izadi-Najafabadi A, Futaba DN, Hata K (2011) A stretchable carbon nanotube strain sensor for human-motion detection. Nat Nanotechnol 6(5):296–301CrossRefGoogle Scholar
  2. 2.
    Cheng Y, Wang R-R, Sun J, Gao L (2015) A stretchable and highly sensitive graphene-based fiber for sensing tensile strain, bending, and torsion. Adv Mater 27(45):7365–7371CrossRefGoogle Scholar
  3. 3.
    Chen L-Z, Weng M-C, Zhang W, Zhou Z, Zhou Y, Xia D, Li J, Huang Z, Liu C, Fan S (2016) Transparent actuators and robots based on single-layer superaligned carbon nanotube sheet and polymer composites. Nanoscale 8(12):6877–6883CrossRefGoogle Scholar
  4. 4.
    Windmiller JR, Wang J (2013) Wearable electrochemical sensors and biosensors: a review. Electroanalysis 25(1):29–46CrossRefGoogle Scholar
  5. 5.
    Amjadi M, Kyung K, Park I, Sitti M (2016) Stretchable, skin-mountable, and wearable strain sensors and their potential applications: a review. Adv Funct Mater 26(11):1678–1698CrossRefGoogle Scholar
  6. 6.
    Gong S, Zhu Z-H (2015) Giant piezoresistivity in aligned carbon nanotube nanocomposite: account for nanotube structural distortion at crossed tunnel junctions. Nanoscale 7(4):1339–1348CrossRefGoogle Scholar
  7. 7.
    Teomete E (2016) The effect of temperature and moisture on electrical resistance, strain sensitivity and crack sensitivity of steel fiber reinforced smart cement composite. Smart Mater Struct 25(7):075024–075034CrossRefGoogle Scholar
  8. 8.
    Tung TT, Robert C, Castro M, Feller J, Kim TY, Suh KS (2016) Enhancing the sensitivity of graphene/polyurethane nanocomposite flexible piezo-resistive pressure sensors with magnetite nano-spacers. Carbon 108:450–460CrossRefGoogle Scholar
  9. 9.
    Choong C-L, Shim M-B, Lee B-S, Jeon S, Ko D-S, Kang T-H, Bae J, Lee SH, Byun K-E, Im J, Jeong YJ, Park CE, Park J-J, Chungn U-I (2014) Highly stretchable resistive pressure sensors using a conductive elastomeric composite on a micropyramid array. Adv Mater 26:3451–3458CrossRefGoogle Scholar
  10. 10.
    Huang Z-M, Liu X-Y, Wu W-G, Li Y-Q, Wang H (2017) Highly elastic and conductive graphene/carboxymethylcellulose aerogels for flexible strain-sensing materials. J Mater Sci 52:12540–12552CrossRefGoogle Scholar
  11. 11.
    Cohen DJ, Mitra D, Peterson K, Maharbiz MM (2012) A highly elastic, capacitive strain gauge based on percolating nanotube networks. Nano Lett 12(4):1821–1825CrossRefGoogle Scholar
  12. 12.
    Cai L, Song L, Luan P, Zhang Q, Zhang N, Gao Q, Zhao D, Zhang X, Tu M, Yang F, Zhou W, Fan Q, Luo J, Zhou W, Ajayan P, Xie S (2013) Super-stretchable, transparent carbon nanotube-based capacitive strain sensors for human motion detection. Sci Rep 3(6157):3048CrossRefGoogle Scholar
  13. 13.
    Guan J, Xing C, Wang Y, Lia Y, Li J (2017) Poly (vinylidene fluoride) dielectric composites with both ionic nanoclusters and well dispersed graphene oxide. Compos Sci Technol 138:98–105CrossRefGoogle Scholar
  14. 14.
    Park S, Ruoff Rodney S (2009) Chemical methods for the production of graphenes. Nat Nanotechnol 4(4):217–224CrossRefGoogle Scholar
  15. 15.
    Zhang M-M, Yan H-X, Yuan L-X, Liu C (2016) Effect of functionalized graphene oxide with hyperbranched POSS polymer on mechanical and dielectric properties of cyanate ester composites. RSC Adv 6(45):38887–38896CrossRefGoogle Scholar
  16. 16.
    Liao W-H, Yang S-Y, Hsiao S-T, Wang Y-S, Li S-M, Ma CCM, Tien H, Zeng S (2014) Effect of Octa(aminophenyl) Polyhedral Oligomeric Silsesquioxane Functionalized Graphene Oxide on the Mechanical and Dielectric Properties of Polyimide Composites. ACS Appl Mater Interfaces 6(18):15802–15812CrossRefGoogle Scholar
  17. 17.
    Yasir BPT, Bobnar V, Gorgieva S, Grohens Y, Finšgar M, Thomas S, Kokol V (2016) Correction: Mechanically strong, flexible and thermally stable graphene oxide/nanocellulosic films with enhanced dielectric properties. RSC Adv 6(54):49138–49149CrossRefGoogle Scholar
  18. 18.
    Lim J, Yeo H, Goh M, Ku BC, Kim SG, Lee HS, Park B, You NH (2015) Grafting of polyimide onto chemically-functionalized graphene nanosheets for mechanically-strong barrier membranes. Chem Mater 27(6):2040–2047CrossRefGoogle Scholar
  19. 19.
    Liu H, Li Y, Dai K, Zheng G, Liu C, Shen C, Yan X, Guo J, Guo Z (2016) Electrically conductive thermoplastic elastomer nanocomposites at ultralow graphene loading levels for strain sensor applications. J Mater Chem C 4(1):157–166CrossRefGoogle Scholar
  20. 20.
    Liu H, Gao J-C, Huang W-J, Dai K, Zheng G, Liu C, Shen C, Yan X, Guo J, Guo Z (2016) Electrically conductive strain sensing polyurethane nanocomposites with synergistic carbon nanotubes and graphene bifillers. Nanoscale 8(26):12977–12989CrossRefGoogle Scholar
  21. 21.
    Ren P-G, Yan D-X, Chen T, Zeng B-Q, Li Z-M (2011) Improved properties of highly oriented graphene/polymer nanocomposites. J Appl Polym Sci 121(6):3167–3174CrossRefGoogle Scholar
  22. 22.
    Yang X-Y, Mei T, Yang J, Zhang C-G, Lv M-J, Wang X-B (2014) Synthesis and characterization of alkylamine-functionalized graphene for polyolefin-based nanocomposites. Appl Surf Sci 305:725–731CrossRefGoogle Scholar
  23. 23.
    Hou Y, Wang D-R, Zhang X-M (2013) Positive piezoresistive behavior of electrically conductive alkyl-functionalized graphene/polydimethylsilicone nanocomposites. J Mater Chem C 1(3):515–521CrossRefGoogle Scholar
  24. 24.
    Chen H, Xiao L, Xu Y, Zeng X, Ye Z-B (2016) A novel nanodrag reducer for low permeability reservoir water flooding: long-chain alkylamines modified graphene oxide. J Nanomater 1:1–9Google Scholar
  25. 25.
    Yao Y, Ning N, Zhang L, Nishi T, Tian M (2015) Largely improved electromechanical properties of thermoplastic polyurethane dielectric elastomer by carbon nanosphere. RSC Adv 5(30):23719–23726CrossRefGoogle Scholar
  26. 26.
    Yang J-S, Huang D-H, Cao Q-L, Li Q-G, Wang L-Z, Wang F-H (2013) Crystallization of polymer chains induced by graphene: molecular dynamics study. Chin Phys B 22(9):98101–98105CrossRefGoogle Scholar
  27. 27.
    Hu L, DSH Grüner G (2014) Percolation in transparent and conducting carbon nanotube networks. Nano Lett 4(12):2513–2517CrossRefGoogle Scholar
  28. 28.
    Luo S-B, Shen Y-B, Yu S-H, Wan Y-J, Liao W-H, Sun R, Wong CP (2017) Construction of a 3D-BaTiO3 network leading to significantly enhanced dielectric permittivity and energy storage density of polymer composites. Energy Environ Sci 10:137–144CrossRefGoogle Scholar
  29. 29.
    Dang Z-M, Yuan J-K, Zha J-W, Zhou T, Li S-T, Hu G-H (2012) Fundamentals, processes and applications of high-permittivity polymer-matrix composites. Prog Mater Sci 57(4):660–723CrossRefGoogle Scholar
  30. 30.
    Khanam PN, Al-Maadeed MA, Mrlik M (2016) Improved flexible, controlled dielectric constant material from recycled LDPE polymer composites. J Mater Sci: Mater Electron 27(8):8848–8855. Google Scholar
  31. 31.
    Sarwar MS, Dobashi Y, Preston C, Wyss JKM, Mirabbasi S, Madden JDW (2017) Bend, stretch, and touch: locating a finger on an actively deformed transparent sensor array. Sci Adv 3(3):1–8CrossRefGoogle Scholar
  32. 32.
    Tian M, Wei Z-Y, Zan X-Q, Zhang L-Q, Zhang J, Ma Q, Ning N, Nishi T (2014) Thermally expanded graphene nanoplates/polydimethylsiloxane composites with high dielectric constant, low dielectric loss and improved actuated strain. Compos Sci Technol 99:37–44CrossRefGoogle Scholar
  33. 33.
    Park J, You I, Shin S, Jeong U (2015) Material approaches to stretchable strain sensors. Chem Phys Chem 16(6):1155–1163CrossRefGoogle Scholar
  34. 34.
    Engheta N (2007) Circuits with light at nanoscales: optical nanocircuits inspired by metamaterials. Science 317(5845):1698–1702CrossRefGoogle Scholar

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Authors and Affiliations

  1. 1.School of Materials Science and EngineeringZhengzhou UniversityZhengzhouChina
  2. 2.School of Electrical EngineeringZhengzhou UniversityZhengzhouChina
  3. 3.Laboratory of Polymer Physics and ChemistryInstitute of Chemistry, The Chinese Academy of SciencesBeijingChina

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