Skip to main content Accessibility help

Microdrop generation and deposition of ionic liquids

  • Víctor J. Cadarso (a1), Julia Perera-Nuñez (a2), Antonio Mendez-Vilas (a2), Luis Labajos-Broncano (a3), Maria-Luisa González-Martín (a3) and Jürgen Brugger (a4)...


This work describes the use of a piezo-actuated inkjet print head with a nozzle aperture of 50 µm to obtain picoliter drops of different model ionic liquids (ILs). A theoretical analysis of the microdrop generation of three model ILs is confirmed by experiments. The inkjet print process was optimized to enable a stable and reproducible drop ejection in both continuous and drop-on-demand modes by controlling the temperature of the nozzle, as well as the electrical signal sent to the piezo actuator used to generate the drops. Controlled volumes ranging from 43 ± 3 pL to 319 ± 1 pL have been achieved, with a volume control down to 3 pL. The null volatility of ILs yields an extremely high stability of the inkjet process, obtaining drops with very constant volumes during the entire print process. It also avoids the coffee staining effect observed in the deposition of conventional liquid drops. The possibility to deposit controlled volumes in a reproducible way is demonstrated here and applied to a proof-of-concept application with the aim to create dense concave optical lens arrays by replicating the deposited ionic liquid microdrops in poly(dimethylsiloxane) (PDMS).


Corresponding author

a) Address all correspondence to these authors. e-mail:


Hide All
1. Plechkova, N.V. and Seddon, K.R.: Applications of ionic liquids in the chemical industry. Chem. Soc. Rev. 37(1), 123 (2008).
2. Rogers, R.D. and Seddon, K.R.: Ionic liquids – Solvents of the future? Science 302(5646), 792 (2003).
3. Weingärtner, H.: Understanding ionic liquids at the molecular level: Facts, problems, and controversies. Angew. Chem., Int. Ed. 47(4), 654 (2008).
4. Seddon, K.R.: Ionic liquids for clean technology J. Chem. Technol. Biotechnol. 68(4), 351 (1997).
5. Wasserscheid, P. and Keim, W.: Ionic liquids – New ‘solutions’ for transition metal catalysis. Angew. Chem., Int. Ed. 39(21), 3773 (2000).
6. Torimoto, T., Tsuda, T., Okazaki, K.I., and Kuwabata, S.: New frontiers in materials science opened by ionic liquids. Adv. Mater. 22(11), 1196 (2010).
7. Borra, E.F., Seddiki, O., Angel, R., Eisenstein, D., Hickson, P., Seddon, K.R., and Worden, S.P.: Deposition of metal films on an ionic liquid as a basis for a lunar telescope. Nature 447(7147), 979 (2007).
8. Grätzel, M.: Dye-sensitized solar cells. J. Photochem. Photobiol., C 4(2), 145 (2003).
9. Trang Pham, T.T., Bessho, T., Mathews, N., Zakeeruddin, S.M., Lam, Y.M., Mhaisalkar, S., and Grätzel, M.: Light scattering enhancement from sub-micrometer cavities in the photoanode for dye-sensitized solar cells. J. Mater. Chem. 22(32), 16201 (2012).
10. Rutten, F.J.M., Tadesse, H., and Licence, P.: Rewritable imaging on the surface of frozen ionic liquids. Angew. Chem., Int. Ed. 46(22), 4163 (2007).
11. Bermúdez, M.D., Jiménez, A.E., Sanes, J., and Carrión, F.J.: Ionic liquids as advanced lubricant fluids. Molecules 14(8), 2888 (2009).
12. Kim, G.T., Jeong, S.S., Xue, M.Z., Balducci, A., Winter, M., Passerini, S., Alessandrini, F., and Appetecchi, G.B.: Development of ionic liquid-based lithium battery prototypes. J. Power Sources 199, 239 (2012).
13. Liu, N., Chen, X., and Ma, Z.: Ionic liquid functionalized graphene/Au nanocomposites and its application for electrochemical immunosensor. Biosens. Bioelectron. 48, 33 (2013).
14. Tordera, D., Meier, S., Lenes, M., Costa, R.D., Ortí, E., Sarfert, W., and Bolink, H.J.: Simple, fast, bright, and stable light sources. Adv. Mater. 24(7), 897 (2012).
15. Tsuchitani, S., Takagi, N., Kikuchi, K., and Miki, H.: Chemical propulsion using ionic liquids. Langmuir 29(9), 2799 (2013).
16. Hozumi, A., Bien, P., and McCarthy, T.J.: Ionic liquids: Nondestructive, nonvolatile imaging fluids for submicrometer-scale monolayer patterns. J. Am. Chem. Soc. 132(16), 5602 (2010).
17. Dubois, P., Marchand, G., Fouillet, Y., Berthier, J., Douki, T., Hassine, F., Gmouh, S., and Vaultier, M.: Ionic liquid droplet as e-microreactor. Anal. Chem. 78(14), 4909 (2006).
18. Perera-Núñez, J., Méndez-Vilas, A., Labajos-Broncano, L., and González-Martín, M.L.: Ionic liquid microdroplets as versatile lithographic molds for sculpting curved topographies on soft materials surfaces. Langmuir 26(22), 17712 (2010).
19. Gao, L. and McCarthy, T.J.: Ionic liquids are useful contact angle probe fluids. J. Am. Chem. Soc. 129(13), 3804 (2007).
20. Palacio, M. and Bhushan, B.: Ultrathin wear-resistant ionic liquid films for novel MEMS/NEMS applications. Adv. Mater. 20(6), 1194 (2008).
21. Pu, J., Wan, S., Zhao, W., Mo, Y., Zhang, X., Wang, L., and Xue, Q.: Preparation and tribological study of functionalized graphene-IL nanocomposite ultrathin lubrication films on Si substrates. J. Phys. Chem. C 115(27), 13275 (2011).
22. Inaba, A., Yoo, G., Takei, Y., Matsumoto, K., and Shimoyama, I.: A Graphene FET Gas Sensor Gated by Ionic Liquid: Proceedings of the IEEE 26th International Conference on Micro Electro Mechanical Systems (Taipei, Taiwan, 2013); p. 969.
23. Mu, X., Wang, Z., Guo, M., Zeng, X., and Mason, A.J.: Fabrication of a Miniaturized Room Temperature Ionic Liquid Gas Sensor for Human Health and Safety Monitoring: Proceedings of the IEEE Biomedical Circuits and Systems Conference: Intelligent Biomedical Electronics and Systems for Better Life and Better Environment (Hsinchu, Taiwan, 2012); p. 140.
24. Mu, X., Wang, Z., Zeng, X., and Mason, A.J.: A robust flexible electrochemical gas sensor using room temperature ionic liquid. IEEE Sens. J. 13(10), 3976 (2013).
25. Ohsawa, K., Takahashi, H., Noda, K., Kan, T., Matsumoto, K., and Shimoyama, I.: A Gas Sensor Based on Viscosity Change of Ionic Liquid: Proceedings of the 24th IEEE International Conference on Micro Electro Mechanical Systems (Cancun, Mexico, 2011); p. 525.
26. Kaisei, K., Kobayashi, K., Matsushige, K., and Yamada, H.: Fabrication of ionic liquid thin film by nano-inkjet printing method using atomic force microscope cantilever tip. Ultramicroscopy 110(6), 733 (2010).
27. Delaney, J.T. Jr., Liberski, A.R., Perelaer, J., and Schubert, U.S.: A practical approach to the development of inkjet printable functional ionogels – bendable, foldable, transparent, and conductive electrode materials. Macromol. Rapid Commun. 31(22), 1970 (2010).
28. Löffelmann, U., Wang, N., Mager, D., Smith, P.J., and Korvink, J.G.: Solvent-free inkjet printing process for the fabrication of conductive, transparent, and flexible ionic liquid-polymer gel structures. J. Polym. Sci., Part B: Polym. Phys. 50(1), 38 (2012).
29. Cadarso, V.J., Perera-Núñez, J., Jacot-Descombes, L., Pfeiffer, K., Ostrzinski, U., Voigt, A., Llobera, A., Grützer, G., and Brugger, J.: Microlenses with defined contour shapes. Opt. Express 19(19), 18665 (2011).
30. Cadarso, V.J., Smolik, G., Auzelyte, V., Jacot-Descombes, L., and Brugger, J.: Heterogeneous material micro-transfer by ink-jet print assisted mould filling. Microelectron. Eng. 98, 619 (2012).
31. De Gans, B.J., Duineveld, P.C., and Schubert, U.S.: Inkjet printing of polymers: State of the art and future developments. Adv. Mater. 16(3), 203 (2004).
32. Wijshoff, H.: The dynamics of the piezo inkjet printhead operation. Phys. Rep. 491(4–5), 77 (2010).
33. Thomas, G.O.: The aerodynamic breakup of ligaments. Atomization Sprays 13(1), 117 (2003).
34. Liu, Y.F., Tsai, M.H., Pai, Y.F., and Hwang, W.S.: Control of droplet formation by operating waveform for inks with various viscosities in piezoelectric inkjet printing. Appl. Phys. A: Mater. Sci. Process. 111(2), 509 (2013).
35. Derby, B.: Inkjet printing ceramics: From drops to solid. J. Eur. Ceram. Soc. 31(14), 2543 (2011).
36. Fromm, J.E.: Numerical calculation of the fluid dynamics of drop-on-demand jets IBM. J. Res. Dev. 28(3), 322 (1984).
37. Reis, N., Ainsley, C., and Derby, B.: Ink-jet delivery of particle suspensions by piezoelectric droplet ejectors. J. Appl. Phys. 97(9), (2005).
38. Jacquemin, J., Husson, P., Padua, A.A.H., and Majer, V.: Density and viscosity of several pure and water-saturated ionic liquids. Green Chem. 8(2), 172 (2006).
39. Freire, M.G., Carvalho, P.J., Fernandes, A.M., Marrucho, I.M., Queimada, A.J., and Coutinho, J.A.P.: Surface tensions of imidazolium based ionic liquids: Anion, cation, temperature and water effect. J. Colloid Interface Sci. 314(2), 621 (2007).
40. Pereiro, A.B., Verdía, P., Tojo, E., and Rodríguez, A.: Physical properties of 1-butyl-3-methylimidazolium methyl sulfate as a function of temperature. J. Chem. Eng. Data 52(2), 377 (2007).


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed