A team of computer scientists in the Department of Computer Science, Saarland University (Saarbrücken, Germany) has developed a technique that enables non-expert users to print their own custom thin film electroluminescent display – and the display can have an integrated touchscreen.
The new technique allow objects made from a variety of materials to be augmented with interactive displays, the displays having different sizes, shapes and resolutions. The team claims that the new technique is both inexpensive and fast and allows the production of a small number of custom displays in “simple environments” such as a user’s home.
The most recent results achieved by the team have been reported in an article entitled “PrintScreen: Fabricating Highly Customizable Thin-film Touch-Displays.” It was published in UIST ‘14 Proceedings of the 27th annual ACM symposium on User interface software and technology Pages 281-290 ACM New York, NY, USA ©2014. A copy of the article is available here. This Display Daily article follows up and amplifies an earlier report from CeBIT (subscription required)
The technique has been named PrintScreen. The team claims that the technique can produce “relatively high resolution” segmented and passive matrix displays. The image produced by the display can be in greyscale or multi-color. A video illustrating PrintScreen display technology appears at the end of this article.
The team has developed two methods to implement the process. Both print an ultra-thin (~120 µm) layer of a special ink that can be easily processed, needing only a low curing temperature. The first method uses conventional screen printing techniques while the second is based on the use of off-the-shelf inkjet printers. The screen printing method is reported as slower but producing a higher quality display. The do-it-yourself display can be printed from a digital template using a program like Microsoft Word or PowerPoint. Both methods have their distinctive strengths and weaknesses, but it is claimed that either process can be implemented by a user within minutes, or in a few hours, depending on the exact procedure used to create the custom display. Readers are referred to the team’s article for details on the means of fabrication and the specifications of the devices that can be produced.
The display can be printed on a variety of deformable and rigid substrates. This includes unconventional materials such as paper, plastics, leather, ceramics, stone, metal and wood. The substrates can be in custom 2D shapes and, if the substrate allows, can be bent, rolled or folded to create 3D surfaces. The display image itself can consist of a single segment, shape, outline or pattern or it can be in the form of raster graphics, multiple segments or other types of structured matrices.
Lead researcher Jürgen Steimle stated that “And if we now combine our approach with 3D printing, we can print three-dimensional objects, which are able to display information and respond to touch as well.” One means of touch input is accomplished by means of a time multiplexed approach in which projected capacitive is sensed utilizing the layers that already exist in the display structure.
Possible applications for these custom displays are diverse and are imagined to extend to mobile and wearable computing applications. Examples offered by the team include the integration of displays into a wide range of everyday and personal items such as paper objects, furniture, household items, briefcases or clothing.
The team reports that it would cost about $21 to cover a standard printer page with a screen printed display layer. Most of the cost is attributable to the cost of the special ink. -Arthur Berman
Saarland University, Jürgen Steimle, +49 (0)681 302 71935, [email protected]
