We manipulate stick objects, such as chopsticks and pens, in our daily life. As the senses of the human hand are sensitive, we can recognize the characteristics of the object touching or manipulating through the stick. Then, we came up with an idea to augment the haptic experience of touching or manipulating something by controlling the property of the stick.

 In this project, we extend the tactile experience with stick-shaped objects used in daily life and create new interactions by realizing stick-shaped devices that change hardness.




 We propose Transtiff, a stick-shaped device with joint stiffness control by artificial muscle mechanism. We focus on stiffness because the stick changes its overall behavior by only controlling the stiffness of its joints. We use a piston mechanism that uses a small motor to compress the liquid in a flexible tube to control the stiffness of the joint.




  1. 小倉 歩, 伊藤 弘大, 伊藤雄一, “人工筋肉機構による硬軟変化関節を備えた棒状インタフェースの提案,” 情報処理学会研究報告, Vol. 2022-EC-65, No. 42, pp. 1-4, Sep. 2022.
  2. Ayumu Ogura, Kodai Ito, Yuichi Itoh, “Transtiff: A Stick Interface with Various Stiffness by Artificial Muscle Mechanism,” UIST ’22 Adjunct: Adjunct Proceedings of the 35th Annual ACM Symposium on User Interface Software and Technology, Article No. 54, pp. 1-3, Oct. 2022.
  3. Ayumu Ogura, Kodai Ito, Shigeo Yoshida, Kazutoshi Tanaka, Yuichi Itoh, “Transtiff: Haptic Interaction with a Stick Interface with Various Stiffness,” ACM SIGGRAPH 2023 Emerging Technologies. 2023. (scheduled to be published)