Dr. Yoshihiro Kawahara: A Ubicomp Life
When our world has embraced new ubicomp technology, who will be the central developers and researchers who are ultimately given credit for this new age. While there could be hundreds of Ubicomp innovators, those who produce diverse technologies that can be implemented almost everywhere will be the defining figures. Dr. Yoshihiro Kawahara certainly checks off this box. For Kawahara, one step into the future is not enough for his life in information communication. Kawahara has been and is involved in several development projects relating to business and energy technology. Meanwhile, his work takes him beyond academic studies and into the realm of tech startups like AgIC, Inc. and SenSprout. Let’s dive into Kawahara’s impact on the world of Ubicomp.
Dr. Yoshihiro Kawahara attended the University of Tokyo in the early 2000’s, earning his Ph.D in Information Communication Engineering in 2005, the same year he joined the university’s faculty as a professor. He is a member of the IEEE MTT TC (specializing in RFID technologies), as well as several other international computing organizations and committees. He has also worked in collaboration with American institutions such as the Georgia Institute of Technology and the MIT Media Labs. With all these institutions on his resume, Kawahara has plenty of projects and research under his belt. Let’s take a dive into some of his more impressive innovations.
Teaching within the School of Engineering of the University of Tokyo, it would make sense that one of Kawahara’s projects goes down to the roots of computing systems. Kawahara and his research partners have taken much inspiration from the use of 3D printing in Ubicomp prototyping for their own electronics prototypes. He has also taken interest in the concept of “digital crafting”, the idea of using less conventional materials to build digital devices and prototypes.
Both of these increasingly popular Ubicomp concepts were put into Kawahara’s development of the Instant Inkjet Circuit. Using everyday inkjet printers (with no specialized software), he was able to demonstrate the power of conductive traces printed onto cheap plastic or paper. With this new method of printing conductive traces, fully functional electronic devices can be fabricated cheaply and with greater flexibility, as the printed conductors have been shown to be quick acting “without the use of any special equipment” (source).
For the world of ubicomp, this presents interesting possibilities to create more flexible, invisible devices, which becomes especially useful when building and testing prototypes. To be more specific, Kawahara identifies in his research paper rapid circuit prototyping, capacitive (storing electronic charge) touch sensing, printed antennas, and other Ubicomp issues as benefiting from his inkjet circuit creation. His research paper on Instant Inkjet Circuits, describing his inspirations and developments, awarded him Best Paper at ACM Ubicomp 2013.
Kawahara has also produced useful information on how to provide flexibility for device energy. Using a sort-of 2-D antenna printed of a flat sheet of paper as a tool of study, a partnership between Kawahara and the Georgia Institute of Technology found a method for harvesting energy from Radio Frequency signals. This antenna would be part of a sensing platform that, in theory, would capture electromagnetic power from these signals indefinitely. This development is impressive, though Kawahara says this will be one step towards his vision of “wireless nodes” that can be spread over a wide area via wind currents (yes, gathering energy while being carried by the wind). This study also seeks to solve issues with power leakage in hopes that the sensors in question will have minimal power shortages.
Similarly, Kawahara has produced intriguing work on harvesting power that’s leaked from microwave ovens in order to power other items in the home. In another research paper featured at ACM Ubicomp 2013, Kawahara addresses issues with batteries used in today’s low-power home devices, and how these low-power devices have great potential to be powered by ambient electricity rather than these annoying batteries. He and his research group demonstrated through experimentation that microwave ovens can provide sufficient ambient power to other home devices. This would allow users to power smaller appliances, low-powered smart devices, electronic toys, and more without needing to purchase and deal with the common issues of button cell batteries.
There’s plenty of work to be done with everyday ubicomp devices, as the public is certainly anticipating new products. Capturing activity has been Kawahara’s major focus, as he’s recognized several improvements that can be made to current smartphone sensor technology. For example, he’s helped develop a better smartphone accelerometer to help track activity as well as calorie meters.
In one study, he promotes the important role that accelerometers could play in curbing cardiovascular disease while presenting challenges that current related devices face. His research group proposes a refined version of a previously proposed model (3-axis accelerometer) that solves the three primary issues facing this technology: limitations on posture inference, issues with sensing multiple body positions during activity, and inefficient use of battery power during computation of statistics. The result of this research and problem-solving was a prototype mobile phone application that demonstrates the accuracy of posture inference, as well as the use of metabolic equivalents (METS) to measure calories. The research has sought to further improve this study, as there are limitations on the posture inference model and test subjects for the application were young and healthy, rather than people who might be at serious risk of cardiovascular disease.
The most impressive ubicomp concept Kawahara has worked on must be “Multi-Hop Wireless Power Transmission.” In short, this technology will allow for power to be routed to different devices via two-dimensional surfaces. In other words, floors and walls will serve as conduits with minimum power loss. This presents a vision of a future where devices spread across your living room, kitchen, or anywhere else can be wirelessly powered without any physical connection between devices.
There are, of course, many more similar studies and projects completed by Kawahara. These exciting projects and research papers have earned Dr. Kawahara over a dozen awards from the IEEE, ACM, Microsoft, and other organizations. He currently works for a huge number workshops, conferences, and committees within the ubicomp and pervasive computing (many associated with the IEEE). Given everything he has done so far and the number of endeavors he is participating in, expect Kawahara’s name to appear in many important publications and news articles as advanced ubicomp technologies become more prevalent in consumer products and business operations. He seems devoted to pushing the boundaries of how power and information flow around us, which means more concepts and innovations are likely on the way.
Bibliography
· “Yoshihiro Kawahara — Profile.” University of Tokyo, https://kawahara.akg.t.u-tokyo.ac.jp.
· Kawahara, Yoshihiro, Xiaoying Bian, Ryo Shigeta, Rushi Vyas, Manos M. Tentzeris, and Tohru Asami. “Power Harvesting from Microwave Oven Electromagnetic Leakage.” ACM Ubicomp 2013, https://dl.acm.org/doi/pdf/10.1145/2493432.2493500. Accessed 9 May 2021.
· Kawahara, Yoshihiro, Steve Hodges, Benjamin S. Cook, Cheng Zhang, and Gregory D. Abowd. “Instant Inkjet Circuits: Lab-based Inkjet Printing to Support Rapid Prototyping of UbiComp Devices.” ACM Ubicomp 2013, https://dl.acm.org/doi/pdf/10.1145/2493432.2493486. Accessed 9 May 2021.
· Kawahara, Yoshihiro, Nanami Ryu, and Tohru Asami. “Monitoring Daily Energy Expenditure using a 3-Axis Accelerometer with a Low-Power Microprocessor.” Graduate School of Information Science and Technology, University of Tokyo, https://docs.google.com/file/d/0B_fn2IMPbZt6MWpsakY3aHlwaU0/edit. Accessed 16 May 2021.
· Wiring Pattern printed on a coated sheet of PET film. University of Tokyo, https://kawahara.akg.t.u-tokyo.ac.jp. Accessed 9 May 2021.
· Illustrate Concept of Multi-Hop Wireless Power Transmission. University of Tokyo, https://kawahara.akg.t.u-tokyo.ac.jp. Accessed 9 May 2021.
· Yoshihiro Kawahara. ResearchGate, https://www.researchgate.net/profile/Yoshihiro-Kawahara/7. Accessed 9 May 2021.
