Gravure printed electronics
Among various printing technologies proposed for printed electronics, gravure printing, which is routinely used for high resolution, large-area printing such as currency, is one of the most suitable technology because of its high throughput, pattern fidelity and large-area printability. However, most of similar high-throughput roll printed transistors were reported to be showing poor performance (i.e. below kHz operation frequency) due to large printed features and thus significantly large parasitic capacitance. In my works, I developed attoliter-scale, high-resolution (sub 5 micron) pattern engraving on the gravure rolls using electromechanical engraving technique for MHz operation high-performance circuits on plastic substrate while printing at ~ 1 m/s.
These extremely consistent engraved cells as small as 2.5 micron allows sub-5µm printed features with very good printed pattern fidelity.
With this technique incorporated with high mass loaded gold nanoparticle ink and high performance solution processed organic semiconductor, I was able to print p-type only inverters operating in MHz on flexible polyethylene naphthalate substrate, much superior to previously reported roll printed circuits with high printing throughput.
I believe knowledge developed in these works provides important insights for commercialization of printed electronics applications.
Publications & Presentations:
- Hongki Kang, Rungrot Kitsomboonloha, Kurt Ulmer, Lisa Stecker, Gerd Grau, Jaewon Jang and Vivek Subramanian, “Megahertz-class printed high mobility organic thin-film transistors and inverters on plastic using attoliter-scale high-speed gravure-printed sub-5 μm gate electrodes,” ORGANIC ELECTRONICS, vol. 15, no. 12, pp. 3639–3647, Dec. 2014. (Link)
- Hongki Kang, Rungrot Kitsomboonloha, Jaewon Jang, and Vivek Subramanian, “High-performance printed transistors realized using femtoliter gravure-printed Sub-10μm metallic nanoparticle patterns and highly uniform polymer dielectric and semiconductor layers,” ADVANCED MATERIALS, vol. 24, no. 22, pp. 3065–3069, 2012. (Link)
- PhD dissertation: Gravure-printed Highly-scaled Organic Thin-film Transistors for Low-cost and Large-area Electronics
- Rungrot Kitsomboonloha, Hongki Kang, and Vivek Subramanian, “High Performance Organic TFTs Using High-Resolution Gravure Printed Electrodes,” Materials Research Society, Boston, US, Fall 2013.
- Gerd Grau, Rungrot Kitsomboonloha, Sarah Swisher, Hongki Kang, and Vivek Subramanian, “Printed Transistors on Paper: Towards Smart Consumer Product Packaging,” LOPE-C, Germany, June 2013.
- (Invited) Vivek Subramanian, Stephen J. S. Morris, Hongki Kang, and Rungrot Kitsomboonloha, “Modeling, Scaling, and Integration of Gravure Printing for Fast Switching Organic FETs,” Materials Research Society, Boston, US, Fall 2012.
- Hongki Kang, Alejandro de la Fuente Vornbrock, Rungrot Kitsomboonloha, Jaewon Jang, and Vivek Subramanian, “Highly-Scaled Gravure Printed organic TFTs with 10 μm channel length on Plastic with 300 kHz operation,” Materials Research Society Spring 2012.
- (Invited) Hongki Kang, Huai-Yuan Tseng, Rungrot Kitsomboonloha, and Vivek Subramanian, “High-performance printed organic transistors: Advances in printing techniques and processes,” 2012 Flexible Electronics & Displays Conference & Exhibition, Phoenix, AZ, Feb 6-9, 2012.
Other related works:
- Gerd Grau, Jialiang Cen, Hongki Kang, Rungrot Kitsomboonloha, William Scheideler, and Vivek Subramanian, “Gravure-printed electronics: Recent progress in tooling development, understanding of printing physics, and realization of printed devices,” FLEXIBLE AND PRINTED ELECTRONICS, 1, 023002, 2016. (Link)
- Rungrot Kitsomboonloha, Hongki Kang, Gerd Grau, William Scheideler, and Vivek Subramanian, “MHz-Range Fully Printed High-Performance Thin-Film Transistors by Using High-Resolution Gravure-Printed Lines,” ADVANCED ELECTRONIC MATERIALS, vol. 1, no. 12, Dec. 2015. (Link)
- Vivek Subramanian, Jialiang Cen, Alejandro de la Fuente Vornbrock, Gerd Grau, Hongki Kang, Rungrot Kitsomboonloha, Daniel Soltman, and Huai-Yuan Tseng, "High-speed printing of transistors: From Inks to Devices," PROCEEDINGS of the IEEE, vol. 103, no. 4, 2015. (Link)
- Gerd Grau, Rungrot Kitsomboonloha, Hongki Kang, and Vivek Subramanian, "High performance printed organic transistors using a novel scanned thermal annealing technology," ORGANIC ELECTRONICS, vol. 20, pp. 150–157, May 2015. (Link)
- Gerd Grau, Rungrot Kitsomboonloha, Sarah L Swisher, Hongki Kang, Vivek Subramanian, “Printed Transistors on Paper: Towards Smart Consumer Product Packaging,” ADVANCED FUNCTIONAL MATERIALS, vol. 24, no. 32, pp. 5067–5074, 2014. (Link)
- Alejandro de la Fuente Vornbrock, Donovan Sung, Hongki Kang, Rungrot Kitsomboonloha, and Vivek Subramanian, "Fully gravure and ink-jet printed high speed pBTTT organic thin film transistors," ORGANIC ELECTRONICS, vol. 11, no. 12, pp. 2037-2044, DEC 2010. (Link)