Introduction
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.
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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.
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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).
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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. Vol. 9, num. 3, p. 1382 – 1390. DOI : 10.1021/acssensors.3c02406. Nanoliter Liquid Packaging in a Bioresorbable Microsystem by Additive Manufacturing and its Application as a Controlled Drug Delivery Device
J. Park; A. Bertsch; C. Martin Olmos; J. Brugger
Advanced Functional Materials. 2023. num. 2302385. DOI : 10.1002/adfm.202302385. Inkjet‐Printed Composites for Room‐Temperature VOC Sensing: From Ink Formulation to Sensor Characterization
M. Kiaee; T. Maeder; J. Brugger
Advanced Materials Technologies. 2020. p. 1 – 11, 2000929. DOI : 10.1002/admt.202000929. A 3D Microscaffold Cochlear Electrode Array for Steroid Elution
J. Jang; J. Kim; Y. C. Kim; S. Kim; N. Chou et al.
Advanced Healthcare Materials. 2019. p. 1900379. DOI : 10.1002/adhm.201900379. Growth of Large-Area 2D MoS2 Arrays at Pre-Defined Locations Using Stencil Mask Lithography
I. Sharma; Y. Batra; V. Flauraud; J. Brugger; B. R. Mehta
Journal of Nanoscience and Nanotechnology. 2018. Vol. 18, num. 3, p. 1824 – 1832. DOI : 10.1166/jnn.2018.14265. Penciling a triboelectric nanogenerator on paper for autonomous power MEMS applications
X. Zhang; M. Su; J. Brugger; B. Kim
Nano Energy. 2017. Vol. 33, p. 393 – 401. DOI : 10.1016/j.nanoen.2017.01.053. 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. 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. 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. 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. 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. Uniformly Dispersed Deposition of Colloidal Nanoparticles and Nanowires by Boiling
K. Lee; M. Duchamp; G. Kulik; A. Magrez; J. W. Seo et al.
Applied Physics Letters. 2007. Vol. 91, num. 17, p. 173112. DOI : 10.1063/1.2803320. MEMS tools for combinatorial materials processing and high-throughput characterization
A. Ludwig; J. Cao; J. Brugger; I. Takeuchi
Measurement Science and Technology. 2005. Vol. 16, num. 1, p. 111 – 118. DOI : 10.1088/0957-0233/16/1/015.
Conference papers
LIQUID-IN-A-MEMS: ENCAPSULATION OF LIQUID IN A MICROCAPSULE BY INKJET PRINTING
J. Park; A. Bertsch; J. Brugger
2023. 22nd International Conference on Solid-State Sensors, Actuators and Microsystems, Kyoto, Japan, 2023-06-25 – 2023-06-29. Printed Polymer Composite Sensors for Low-Power, Near Room-Temperature Detection and Classification of VOCS
M. Mahdi Kiaee; T. Maeder; J. Brugger
2021. 34th International Conference on Micro Electro Mechanical Systems (IEEE MEMS 2021), Gainesville, FL, USA (virtual event), January 25-29, 2021. p. 274 – 277. DOI : 10.1109/MEMS51782.2021.9375208. 3D Printed Micro-Scaffolds Loaded by Inkjet Printing With in-Precise Amount of Drug
F. Zheng; J. Jang; C. Tse; J. Brugger
2020. 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. 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. Self-assembly of micro/nanosystems across scales and interfaces
M. Mastrangeli
2017. 19th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS 2017), Kaohsiung, Taiwan, June 18-22, 2017. p. 676 – 681. DOI : 10.1109/TRANSDUCERS.2017.7994139. Liquid-Filled Sealed Mems Capsules Fabricated By Fluidic Self-Assembly
M. Mastrangeli; L. Jacot-Descombes; M. R. Gullo; J. Brugger
2014. IEEE International Conference on Micro Electro Mechanical Systems (MEMS 2014), San Francisco (USA), January 26-30, 2014. p. 56 – 59. DOI : 10.1109/MEMSYS.2014.6765572. Automated Real-Time Control of Fluidic Self-Assembly of Microparticles
M. Mastrangeli; F. S. Schill; J. Goldowsky; H. Knapp; J. Brugger et al.
2014. 2014 IEEE International Conference on Robotics and Automation (ICRA 2014), Hong Kong (China), May 31 – June 7, 2014. p. 5860 – 5865. DOI : 10.1109/ICRA.2014.6907721. New inks for the direct drop-on-demand fabrication of polymer lenses
A. Voigt; U. Ostrzinski; K. Pfeiffer; J. Y. Kim; V. Fakhfouri et al.
2011. 36th International Conference on Micro & Nano Engineering (MNE), Genoa, Italy, September 19-22, 2010. p. 2174 – 2179. DOI : 10.1016/j.mee.2010.12.004. 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.. High-Fidelity Printing Strategies for Printing 3D Vascular Hydrogel Structures
K. Pataky; M. Ackermann; T. Braschler; M. Lutolf; P. Renaud et al.
2009. 25th International Conference on Digital Printing Technologies, Louisville, KY, Sep 20-24, 2009. p. 411 – 414. 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.. Novel methods to pattern polymers for microfluidics
C. Martin; A. Llobera; T. Leïchlé; G. Villanueva; A. Voigt et al.
2008. 33rd International Conference on Micro- and Nano Engineering 2007 (MNE 2007), Copenhagen, Denmark, 23-26 Sept, 2007. p. 972 – 975. DOI : 10.1016/j.mee.2008.01.052. 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.