How can the computer facilitate interpersonal joint action, which is the collaborative action conducted by multiple persons? To explore this research question, we develop EMAS (ElectroMagnetic Actuation System): a motion transfer system using electromagnets, allowing the users to share their finger motion.

EMAS consisting of wearable magnets and electromagnets can drive finger motions such as button pressing with a low latency of less than 16 ms. With this low-latency actuation, the system also can control the transfer direction such as mono-direction or bi-direction among multiple persons. Based on the realtime motion transfer, we’re investigating a new kind of computer-assisted joint action.

Credit :

Daisuke Tajima (Sony Computer Science Laboratories, Inc.)
Taku Tanichi (Sony Computer Science Laboratories, Inc., Keio Media Design)
Shehata Mohammad H (California Institute of Technology, Toyohashi University of Technology)
Shunichi Kasahara (Sony Computer Science Laboratories, Inc.)


Joint action, performing a task together by multiple people, can be beneficial in transferring the embodied skill, establishing physical relationships, engaging multiple people, and completing the task more effectively. To facilitate real-time joint bodily action, we introduce a low-latency motion transfer system (total latency: 22.9 ± 2.0 ms, finger attraction latency: 13.7 ± 2.1 ms) using electromagnetic actuation, which allows them to share their instantaneous actions, such as pressing the button with their fingers. Our system can change the type of motion transfer at both the direction of the transfer between users (mono- or bi-direction) and the input logic (“AND” or “OR”) based on the users’ input. We will discuss its potential as a computer-assisted joint action and the possibility that the computer system orchestrates the joint action between the users or the user and the computer.


Daisuke Tajima, Taku Tanichi, Shehata Mohammad H., and Shunichi Kasahara. 2022. Low-Latency Motion Transfer with Electromagnetic Actuation for Joint Action. In SIGGRAPH Asia 2022 Emerging Technologies (SA ’22 Emerging Technologies). Association for Computing Machinery, New York, NY, USA, Article 6, 1–2.

Posted by:shunichikasahara