Inkjet Printing


Drop-on-demand inkjet-printing (DOD IJP) is a versatile digital printing technique that allows for direct patterning of a wide range of functional materials such as polymers, polymer composites, as well as different types of nanomaterials. In this technique, pico-liter droplets are generated and precisely positioned on substrates. The possibility of positioning a small volume of material precisely on the substrate as well as contactless patterning has made DOD IJP an interesting technique in the fields such as fabricating optical components (e.g. microlens arrays), electronic devices (e.g. thin film transistors), sensors (e.g. chemical sensors), as well as tissue engineering (i.e. cell patterning).

Working principle and some examples

In LMIS1 we are using a piezo-actuated drop-on-demand inkjet printer developed by Microfab Technology. In this printer, the dispenser consists of an annular piezoelectric element, which is attached to a capillary glass tube. When a pulsed voltage waveform is applied to the piezo-element a sudden change of volume occurs in the capillary glass that generates acoustic pressure waves inside the capillary tube and consequently expels a small volume of liquid from the orifice. For droplets to be generated physical properties of the ink e.g. viscosity and surface tension, have to be carefully tuned and printing parameters (e.g. applied waveform) have to be optimized. The image below shows how a droplet is generated from an ink containing a polymer, using a piezo-actuated nozzle.

Figure 1: Generation of pico-liter droplets using a piezo-actuated DOD IJP.

Liquid encapsulation in microdevices

Current technology allows us to create amazingly small physical devices. However, the precise deposition and protection of pL volumes of liquid need to be improved as a consequence. The time-window to encapsulate picolitres of water-based ink is less than a minute before significant evaporation takes place. The loss of liquid can disturb the concentrations contained within the ink for correct function. We use DOD IJP to print our desired ink into defined open vessels. We immediately print an oil-based UV-curable encapsulating layer. Thereafter upon UV curing, crosslinking occurs and forms a barrier to protect the underlying ink from evaporation and external influence.

Figure 2: PDMS samples with wells of 300µm internal lengths are filled with a water-based ink. Before complete evaporation takes place, an immiscible ink is deposited on top to encapsulate the ink underneath before UV treatment.

Printing polymer composites for gas sensing applications

One of the ongoing research activities in our lab regarding IJP is to formulate inks containing polymer nanocomposites (PNCs) for applications in chemical gas sensing using sensor arrays (i.e. electronic nose devices). Since IJP enables us to directly deposit functional materials on a substrate it is a suitable technique for fabricating sensor arrays where each sensor consists of a different material. For this aim we formulate inks containing PNCs, study their printability and investigate their response to different volatile organic compounds (e.g. acetone, and ethanol).

Figure 3: The image (a) shows an exploded view of the sensor device used for characterization of inkjet-printed polymer composites. The image (b) demonstrate working principle of chemiresistive sensors based on polymer composites. The image (c) shows a representative result indicating the response of a printed polystyrene/carbon black composite to acetone. The inset of the image shows a picture of the printed sensor.

Keywords: inkjet, ink-jet, microlense, microdrop

Journal papers


Near-Room-Temperature Detection of Aromatic Compounds with Inkjet-Printed Plasticized Polymer Composites

M. M. Kiaee; T. Maeder; J. Brugger 

Acs Sensors. 2024-03-13. Vol. 9, num. 3, p. 1382-1390. DOI : 10.1021/acssensors.3c02406.

Inkjet‐Printed Composites for Room‐Temperature VOC Sensing: From Ink Formulation to Sensor Characterization

M. Kiaee; T. Maeder; J. Brugger 

Advanced Materials Technologies. 2020-12-06.  p. 1-11, 2000929. DOI : 10.1002/admt.202000929.

Microdrop generation and deposition of ionic liquids

V. J. Cadarso; J. Perera-Nunez; A. Mendez-Vilas; L. Labajos-Broncano; M-L. Gonzalez-Martin et al. 

Journal Of Materials Research. 2014. Vol. 29, num. 17, p. 2100-2107. DOI : 10.1557/jmr.2014.162.

Inkjet printed superparamagnetic polymer composite hemispheres with programmed magnetic anisotropy

O. Ergeneman; C. Peters; M. R. Gullo; L. Jacot-Descombes; S. Gervasoni et al. 

Nanoscale. 2014. Vol. 6, p. 10495-10499. DOI : 10.1039/C3NR06442E.

PDMS-based, magnetically actuated variable optical attenuators obtained by soft lithography and inkjet printing technologies

S. De Pedro; V. J. Cadarso; X. Munoz-Berbel; J. A. Plaza; J. Sort et al. 

Sensors And Actuators A-Physical. 2014. Vol. 215, p. 30-35. DOI : 10.1016/j.sna.2014.01.021.

Inkjet Printing of High Aspect Ratio Superparamagnetic SU-8 Microstructures with Preferential Magnetic Directions

L. Jacot-Descombes; M. R. Gullo; V. J. Cadarso; M. Mastrangeli; O. Ergeneman et al. 

Micromachines. 2014. Vol. 5, p. 583-593. DOI : 10.3390/mi5030583.

Fabrication of HepG2 Cell Laden Collagen Microspheres using Inkjet Printing

J. Ho Choi; Y. Ho Kim; L. Jacot-Descombes; J. Brugger; G. Man Kim 

Journal of the Korean Society for Precision Engineering. 2014. Vol. 31, num. 8, p. 743-747. DOI : 10.7736/KSPE.2014.31.8.743.

Inkjet-printed SU-8 Hemispherical Microcapsules and Silicon chip Embedding

L. Jacot-Descombes; R. M. Gullo; M. Mastrangeli; V. J. Cadarso; J. Brugger 

IET Micro & Nano Letters. 2013. Vol. 8, num. 10, p. 633-636. DOI : 10.1049/mnl.2013.0241.

Simple and easily controllable parabolic-shaped microlenses printed on polymeric mesas

J. Y. Kim; C. Martin-Olmos; N. S. Baek; J. Brugger 

Journal Of Materials Chemistry C. 2013. Vol. 1, num. 11, p. 2152-2157. DOI : 10.1039/c3tc00632h.

Heterogeneous material micro-transfer by ink-jet print assisted mould filling

J. V. Cadarso; G. Smolik; V. Auzelyte; L. Jacot-Descombes; J. Brugger 

Microelectronic Engineering. 2012. Vol. 98, p. 619-622. DOI : 10.1016/j.mee.2012.04.025.

Fabrication of epoxy spherical microstructures by controlled drop-on-demand inkjet printing

L. Jacot-Descombes; R. M. Gullo; C. Busto; V. Javier; J. Brugger 

Journal of Micromechanics and Microengineering. 2012. Vol. 22, num. 7, p. 074012. DOI : 10.1088/0960-1317/22/7/074012.

Nanocomposites based on highly luminescent nanocrystals and semiconducting conjugated polymer for inkjet printing

E. Binetti; C. Ingrosso; M. Striccoli; P. Cosma; A. Agostiano et al. 

Nanotechnology. 2012. Vol. 23, num. 7, p. 075701. DOI : 10.1088/0957-4484/23/7/075701.

Directly fabricated multi-scale microlens arrays on a hydrophobic flat surface by a simple ink-jet printing technique

J. Y. Kim; K. Pfeiffer; A. Voigt; G. Gruetzner; J. Brugger 

Journal of Materials Chemistry. 2012. Vol. 22, num. 7, p. 3053-3058. DOI : 10.1039/c2jm15576a.

Microdrop Printing of Hydrogel Bioinks into 3D Tissue-Like Geometries

K. Pataky; T. Braschler; A. Negro; P. Renaud; M. P. Lutolf et al. 

Advanced Materials. 2012. Vol. 24, num. 3, p. 391-396. DOI : 10.1002/adma.201102800.

Microlenses with defined contour shapes

V. J. Cadarso Busto; J. Perera-Núñez; L. Jacot-Descombes; K. Pfeiffer; U. Ostrzinski et al. 

Optics Express. 2011. Vol. 19, num. 19, p. 18665. DOI : 10.1364/OE.19.018665.

Hybrid polymer microlens arrays with high numerical apertures fabricated using simple ink-jet printing technique

J. Y. Kim; N. B. Brauer; V. Fakhfouri; D. Boiko; E. Charbon et al. 

Optical Materials Express. 2011. Vol. 1, num. 2, p. 259-269. DOI : 10.1364/OME.1.000259.

Drop-on-demand inkjet printing of highly luminescent CdS and CdSe@ZnS nanocrystal based nanocomposites

C. Ingrosso; J. Y. Kim; E. Binetti; V. Fakhfouri; M. Striccoli et al. 

Microelectronic Engineering. 2009. Vol. 86, p. 1124-1126. DOI : 10.1016/j.mee.2008.11.028.

Inkjet-Printed Multicolor Arrays of Highly Luminescent Nanocrystal-Based Nanocomposites

J. Y. Kim; C. Ingrosso; V. Fakhfouri; M. Striccoli; A. Agostiano et al. 

Small. 2009. Vol. 5, p. 1051-1057. DOI : 10.1002/smll.200801315.

Drop-On-Demand Inkjet Printing of SU-8 Polymer

V. Fakhfouri; G. Mermoud; J. Y. Kim; A. Martinoli; J. Brugger 

Micro and Nanosystems. 2009. Vol. 1, num. 1, p. 63-67. DOI : 10.2174/1876402910901010063.

Conference papers


3D Printed Micro-Scaffolds Loaded by Inkjet Printing With in-Precise Amount of Drug

F. Zheng; J. Jang; C. Tse; J. Brugger 

2020-01-01. IEEE 15th International Conference on Nano/Micro Engineered and Molecular System (NEMS), ELECTR NETWORK, Sep 27-30, 2020. p. 426-429. DOI : 10.1109/NEMS50311.2020.9265525.

Film Morphology Effect on VOC Sensor Performance Fabricated by Drop-On-Demand Inkjet-Printing

M. M. Kiaee; T. Maeder; J. Brugger 

2019-06-23. 20th International Conference on Solid-State Sensors, Actuators and Microsystems and Eurosensors XXXIII (TRANSDUCERS and EUROSENSORS), Berlin, Germany, Jun 23-27, 2019. p. 1361-1364. DOI : 10.1109/TRANSDUCERS.2019.8808652.

Inkjet-printing polymer nanocomposite for detecting VOCs

M. Kiaee; T. Maeder; J. Brugger 

2018-09-09. Eurosensors, Graz, September 9-12,2018.

UV-Imprinting and Inkjet Printing – A Technology Synergy for Microlens Manufacturing

L. Jacot-Descombes; V. J. Cadarso; A. Schleunitz; S. Gruetzner; J. Brugger et al. 

2014. 13th International Conference on Nanoimprint and Nanoprint Technology (NNT 2014), Kyoto, Japan, October 22-24.

Polymeric hemispherical pico-liter micro cups fabricated by inkjet printing

L. Jacot-Descombes; M. R. Gullo; V. J. Cadarso; M. Mastrangeli; J. Brugger 

2013. 2013 8th IEEE International Conference on Nano/Micro Engineered and Molecular Systems (NEMS), Suzhou, China, 7-10 04 2013. p. 1119-1122. DOI : 10.1109/NEMS.2013.6559918.

Fabrication of polymeric micro structures by controlled drop on demand inkjet printing

L. Jacot-Descombes; R. M. Gullo; V. J. Cadarso Busto; J. Brugger 

2011. 22nd Micromechanics and Micro systems Europe Workshop, Toensberg, Norway, June 19-22, 2011. p. 97-100.

Direct Fabrication of Polymer Micro lens Arrays having Tunable Optical Properties using Drop-On-Demand Ink-Jet Printing Technology

J. Y. Kim; V. Fakhfouri; K. Pfeiffer; A. Voigt; M. Fink et al. 

2009. 25th International Conference on Digital Printing Technologies, Louisville, KY, Sep 20-24, 2009. p. 803-805.

Nanostencil and InkJet Printing for Bionanotechnology Applications

K. Pataky; O. Vazquez-Mena; J. Brugger 

2009. Nano-Net 2009, 4th International ICST Conference on Nano-Networks, Luzern, Switzerland, October 18-20, 2009..

Drop-on-demand Ink-jet printing of functional materials: Case studies of SU-8 and NCs-embedded Polymer nanocomposites

J. Y. KIM; V. Fakhfouri; C. Ingrosso; M. Striccoli; M. L. Curri et al. 

2008. International Conference on Digital Fabrication Technologies, Pittsburgh, Pennsylvania, USA, September 7-12, 2008..

Inkjet printing of SU-8 for polymer-based MEMS a case study for microlenses

V. Fakhfouri; N. Cantale; G. Mermoud; J. Y. Kim; D. Boiko et al. 

2008. 21st IEEE International Conference on Micro Electro Mechanical Systems 2008, Tucson, Arizona, USA, Jan 13-17, 2008. p. 407-410. DOI : 10.1109/MEMSYS.2008.4443679.