publications

2025

1. UIST

   

   Ultra-low-power ring-based wireless tinymouse

   Yifan Li, Masaaki Fukumoto, Mohamed Kari, and 6 more authors

   In Proceedings of the 38th Annual ACM Symposium on User Interface Software and Technology, Busan, Republic of Korea, 2025

   Abs DOI PDF Video Code

   Wireless mouse rings offer subtle, reliable pointing interactions for wearable computing platforms. However, the small battery below 27 mAh in the miniature rings restricts the ring’s continuous lifespan to just 1-10 hours, because even low-powered wireless communication such as BLE is power-consuming for ring’s continuous use. The ring’s short lifespan frequently disrupts users’ mouse use with the need for frequent charging. This paper presents picoRing mouse, enabling a continuous ring-based mouse interaction with ultra-low-powered ring-to-wristband wireless connectivity. picoRing mouse employs a coil-based impedance sensing named semi-passive inductive telemetry, allowing a wristband coil to capture a unique frequency response of a nearby ring coil via a sensitive inductive coupling between the coils. The ring coil converts the corresponding user’s mouse input into the unique frequency response via an up to 449 uW mouse-driven modulation system. Therefore, the continuous use of picoRing mouse can last approximately 600 (8hrs use/day)-1000 (4hrs use/day) hours on a single charge of a 27 mAh battery while supporting subtle thumb-to-index scrolling and pressing interactions in real-world wearable computing situations.

2. CHI

   

   Demo of picoRing mouse: ultra-low-powered wireless mouse ring with ring-to-wristband coil-based impedance sensing

   Yifan Li, Masaaki Fukumoto, Mohamed Kari, and 4 more authors

   In Proceedings of the Extended Abstracts of the CHI Conference on Human Factors in Computing Systems, Yokohama, Japan, 2025

   Abs DOI PDF

   Wireless mouse rings offer subtle, reliable pointing interactions for wearable computing platforms. However, the small battery below 27 mAh in the miniature rings restricts the ring’s continuous lifespan to just 1-2 hours, because current low-powered wireless communication such as BLE is power-consuming for ring’s continuous use. The ring’s short lifespan persistently disrupts users’ mouse use with the need for frequent charging. This interactivity demonstrates picoRing mouse, enabling a continuous ring-based mouse interaction with ultra-low-powered ring-to-wristband wireless communication. picoRing mouse employs a coil-based impedance sensing named semi-passive inductive telemetry, allowing a wristband coil to capture a unique frequency response of a nearby ring coil via a sensitive inductive coupling between the coils. The ring coil converts the corresponding user’s mouse input into the unique frequency response via an 820 uW mouse-driven modulation module. Therefore, continuous use of picoRing mouse can potentially last over 92 hours on a single charge of a 20-mAh small battery.

3. TEI

   

   Plug-n-play e-knit: prototyping large-area e-textiles using machine-knitted magnetically-repositionable sensor networks

   Yifan Li, Ryo Takahashi, Wakako Yukita, and 7 more authors

   In Proceedings of the Nineteenth International Conference on Tangible, Embedded, and Embodied Interaction, Bordeaux, France, 2025

   Abs DOI PDF

   Prototyping electronic textile involves embedding electronic components into fabrics to develop smart clothing with specific functionalities. However, this process is still challenging since the complicated wiring setup is required during experimental phases. This paper presents plug-n-play e-knit, a large-scale, repositionable e-textile for providing trial-and-error prototyping platforms across the textile. Plug-n-play e-knit leverages industrial digital knitting machines loaded with conductive thread to automatically embed a communication and power supply network into garments, in addition to using soft magnet connectors to rearrange electronic components while preserving the stretchability of the garment. These combinations enable users to quickly establish e-textile sensor networks, and moreover test the performance and optimal placement of the electric devices on the textile. We demonstrated that our textiles leveraging custom I2C protocols could achieve the motion-resilient motion-tracking sensor network over a 2700 cm2 garment area.

2023

1. Privacy Preserved Federated Learning for Skin Cancer Diagnosis

   Yifan Li, Yuechen He, Yufei Fu, and 1 more author

   In 2023 IEEE 3rd International Conference on Power, Electronics and Computer Applications (ICPECA), 2023

   DOI