New Shoes? No Problem. Creating Dynamic Fashion with Wearable Displays
A research team used an e-Paper display to create a color and pattern-changing shoe. Their paper on this project, “Wearable Display for Dynamic Spatial and Temporal Fashion Trends,” will be presented at Display Week’s technical symposium on Wednesday, June 4.
by Wallen Mphepö, Jiaqi Gao, Miao Li, Justin Wang, Mega Mengmeng, Tian Dan, Hanson Zhao, Guilan Yang, Yirui Liu, and YinLei Liu
ACCORDING to recent research, approximately 13 billion pairs of shoes are sold each year. The average woman in developed countries owns approximately 19 pairs of shoes at any given time. The same research shows that of these 19 pairs of shoes up to 75% are rarely worn, usually because they do not match the owner’s outfits. Our research team determined that wearable flexible-display technology could be used to provide a new and dynamic fashion paradigm (while also freeing up needed space in people’s closets!). In this article, we describe a prototype high-heeled shoe that can change colors and patterns via a smartphone, electronics, and a flexible customized e-Paper display.
In the Service of Fashion
The term wearable display brings to mind images of Google Glass or clothes with flashing LEDs patched on them – technology statements rather than fashion statements. It would be short sighted to imagine these as the best realms for wearable displays. From the beginning, our team strove to create technology that would serve fashion, not the other way around.
In the display industry, there is currently an understandable emphasis on full color, extremely fast video refresh rate, and higher than retina resolutions. For our project, we chose to concentrate on e-Paper – a display technology that is monochrome, has slower refresh rates, and lower resolution – potential advantages that are often overlooked and underutilized. In fashion, there are many products that commonly occur in plain black, white, gray, or brown. If the reader will simply assess a random sample of shoes, belts, wallets, bags, etc., wherever she or he is right now, this will be confirmed. A glance at furniture, appliances, vehicle surfaces, and so forth tells the same story. In addition, these surfaces rarely require a video refresh rate!
If we had chosen instead to use a flexible display based on current OLED technology, we could have provided full color, high resolution, fast video refresh rate, an infinite contrast ratio, and so forth. While the result would have been impressive and trendy in terms of displays, it would not have sold for an affordable price, nor would consumers, after paying a handsome amount, be satisfied with its very short battery life. With e-Paper, we still achieved a final product demonstration that offers dynamic functionality and falls squarely in the middle of the price range of current conventional high-fashion shoes ($150 – $250 range).
A New Display Platform
There are many parameters that affect the quality and comfort of a high-heeled shoe. Figure 1 shows a couple of points of interest that need to be taken into consideration.
Of particular importance to note in high heels is the area where the foot bends at the base of the toes. A shoe can be made to be both comfortable and aesthetically pleasing even with a 9-cm heel height as long as the angles and the materials are chosen carefully. This height was chosen to demonstrate that with good design one can achieve some daring heel heights without the shoe being uncomfortable to the wearer or unusable for the technology. The technology we developed works with different extremes of this challenging form factor. For example, the latest electronics board we have developed is just 4 cm long × 3 cm wide × 0.5 cm high. It can fit into most flat shoe heels without a problem. However, a high heel seemed like a challenge that would more visibly illustrate the versatility and fashion-forward nature of our project.
Wearable displays on unconventional surfaces such as shoes do require careful planning and execution. After we chose a high-heeled shoe for our application, we proceeded to check the various parameters that would affect the displayed image quality on such curved surfaces with obvious and not so obvious mechanical stress and strain points that might affect the display’s performance. In particular, we considered the impact on image contrast ratio, viewing angle, and image distortion due to deformations. Our choice of display substrate was made on the basis that it would not suffer greatly from the impact of walking or dirt. Our choice of display-cell sealing method was influenced more by the necessity of protecting it from water. (The exact materials and methodologies used to create this display are the subject of an upcoming paper.)
Fig. 1: A high heel was not necessary to house the electronics, but the researchers determined that a fairly high-heeled (9.5 cm) shoe would showcase the fashion aspect of the project to the best possible extent.
The Electronics and the Display
An understanding of shoe mechanics enables one to choose the most appropriate location to place the electronics to both drive the display as well as perform other wearable computing functions. Minimizing the volumetric size of the electronics is crucial for most wearables. From our design and iterations, we calculated that a volume of 4.5 cm × 4 cm × 1.5 cm would just be small enough to suffice for a women’s size 38 shoe and would fit inside the heel of the shoe.
To achieve this, we employed a well-known prototyping board, the Arduino, and customized it with additional chips (Fig. 2), including a Bluetooth chip for wireless communication with the user’s smartphone. We wrote an Arduino script and uploaded it to the custom board. We then built an Android app to send the commands to the board via Bluetooth in order to control the displayed images we had previously
photographed with the smartphone camera and transfer them to the shoe display.
For this prototyping purpose, we used a customized flexible e-Paper display powered by a rechargeable 3-V lithium-ion battery. The battery had sufficient power for the rest of the electronics as well. It should last from 6 months to 2 years depending on usage.
Fig. 2: The front of the customized printed circuit board placed in the heel of the shoe is shown at left and the back is shown at right.
Smart-Shoe Issues and Challenges
Figure 3 shows sample screenshots from a demo video of a user operating our custom Android app to control the shoe’s appearance at the click of a button. xPatterns are also possible. Some of the challenges we faced in realizing this “smart shoe” stemmed from the fact that the display itself had to be a custom shape and use custom substrates that work well with conventional leather shoes. The shoe itself had to be designed from the ground up to seamlessly incorporate the display, the display wiring, and the display powering. It took a few iterations to settle on the recipe, as both display properties and shoe properties had to be meshed just right. A compromise in either the shoe’s or the display’s properties would not do if it meant the result was neither pretty nor functional.
The impact of this rather slow, monochrome, and low-resolution display is evident. The ability to dynamically change the appearance of the footwear to match various outfits has value both in terms of fashion and practicality. Ad-hoc self-expression and personalization do not need to look tacky or awkward. With this design, there is no hint that the electronics are there.
However, with new platforms come new quandaries. One topic that has emerged is the ease with which trademarked art, patterns, and logos might be scanned and redeployed on other merchandise. This is but one of the many potential topics that this frontier in wearable technologies and wearable displays in particular will make it necessary to address. However, as with the movie industry and the music industry before it, disruptive platforms do not necessarily bring about the doom that many analysts predict. Indeed, both the music and movie industry are alive and well years after Sean Parker introduced the MP3 format, although both industries have seen a shift in terms of business models.
In a random survey conducted by the authors, an overwhelming majority – 98% – of women were in favor of fashion products and accessories that can be
dynamically changed with a smartphone app to match their desired ensemble. Out of 240 women, 236 were in favor; the other four were not sure what it meant to change the appearance of their accessories using a smartphone app because they could not imagine it. Of those in favor, their condition was that it should not look, feel, weigh, or smell like a fashion product compromised to accommodate electronics. Designers will have to tread a fine line between efficiency and appearance in order to avoid the spectacle of “geek fashion.”
We are still cautiously exploring what custom information content to allow while we retain control over the technology for now. As with most technologies, especially new ones, we are aware that this could be abused, ala SnapChat, before it settles into conventional legitimate intended uses. Some parties have already come to us with requests for the ability to display on demand their dating status, job searching status, horoscope signs, personal codes and QR codes, etc. It is, in particular, the personal codes and QR codes that can easily be abused since they can point to a Web site or half a page’s worth of text that can be set arbitrarily by the user to anything, including test answers, formulas, photos, etc.
Fig. 3: The image at left shows the shoe in a neutral white design. At right, the shoe has been changed to a black design to match a hypothetical user’s outfit.
A Foot in the Door
We are pleased that we were able to develop a prototype that is a regular shoe in all aspects except it has a hidden technological capability to change its
patterns and colors via a smartphone app. This technology is product modular and applicable to other markets as well. We have already been approached by representatives from a couple of companies that prefer not to be named as they are still in the very early stages of designing luxury concept vehicles. As for the clothing market, we are already in the process of customizing the technology to work with a variety of women’s dresses. Purses and bags, on the other hand, are just a simple modification of the current shoe platform.
As of writing this magazine article, we are finalizing a collaboration agreement with a division of Intel’s Wearable Technology R&D (http://www.intel.com/content/www/us/en/do-it-yourself/edison.html). We have just signed an agreement with the European shoe brand United Nude (www.unitednude.com) to implement our updated platform into four of their designer product lines. We have already signed an agreement with Dragon Innovation, Inc. (www.dragoninnovation.com), the company that assisted Pebble in reaching a record Kickstarter funding of $10 million to help us with Crowdfunding campaign preparation services. The crowdfunding pledges will enable us to keep pushing boundaries until we secure funding to fully scale.
We envision that at some point most clothes will come with wearable technology by default.
Clearly, this is not going to happen overnight nor is it guaranteed. We are determined to stay true to our startup vision of wearable technology that is powerful, ubiquitous, yet largely invisible behind the true design form factor.
A great many thanks go to Dean Susan McDougal, Colby College; Lovemore Matemera Embassy Consular in Beijing; and George Goma Secretary to Ambassador Embassy in Beijing.
1Global Industry Analysts Footwear Report (2012).
2H. A. Macleod, “Thin-film Optical Filters,” 3rd ed. (IoP, CRC Press, 2001), Chapters 2 & 8.
3R. A. M. Hikmet and H. Kemperman, “Electrically switchable mirrors and optical components made from liquid-crystal
gels,” Nature 392, 476–479 (1998).
4N. Y. Ha, Y. Ohtsuka, S. M. Jeong, S. Nishimura, G. Suzaki, Y. Takanishi, K. Ishikawa, and H. Takezoe, “Fabrication of a simultaneous red–green–blue reflector using single-pitched cholesteric liquid crystals.” Nature Materials 7, 43–47 (2008).
5L. D. Negro, M. Stolfi, Y. Yi, J. Michel, X. Duan, L. C. Kimerling, J. Leblanc, and J. Haavisto, “Photon band gap properties and omnidirectional reflectance in Si/SiO2 Thue–Morse quasicrystals,” Appl. Phys. Lett. 84, 5186–5188 (2004).
6Light Machinery, Inc., Light Machinery Online Calculators – Thin Film CAD. Available http://www.lightmachinery.com/Thin-film-CAD841.htm
7Qualcomm, Inc., “How MEMS-based IMOD technology works.” Available http://www.mirasoldisplays.com/mobile-display-imod-technology.php?p=2&techID=2 •