A Soft Robotic Tongue-Mechatronic Design and Surface Reconstruction

• Published in: IEEE/ASME transactions on mechatronics Vol. 22; no. 5; pp. 2102 - 2110
• Main Authors: Lu, Xuanming, Xu, Weiliang, Li, Xiaoning
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Actuation; Deformation; Elongation; Extensibility; Finite element method; Human motion; Motion control; Motion tracking; Movement; Muscles; pneumatic actuation; Pneumatic systems; Polydimethylsiloxane; Pressure sensors; Reconstruction; robotic tongue; Robotics; Robots; Rubber pad forming; Silicone rubber; Soft robotics; Structural design; Surface reconstruction; Three dimensional printing; Tongue; Valves
• ISSN: 1083-4435; 1941-014X
• DOI: 10.1109/TMECH.2017.2748606

A novel soft robot mimicking the human tongue's motion is proposed for the purpose of measuring the tongue movement and interaction with its surrounding in vitro. In order to gain verisimilitude and flexibility, the robotic tongue is simplified from a biological tongue and is made of soft materials, including silicone rubber forming the extensible layer and polydimethylsiloxane composing the less extensible layer. The robotic tongue can deform when pressurized in a series of embedded chambers due to the difference in strain of the two layers. General deformation results are obtained through finite-element method simulations and initial parameters of the structural design are improved. The robotic tongue is fabricated with 3-D printed molds by curing the silicone rubber at room temperature. The pneumatic actuation system is mainly composed of solenoid directional valves and pressure sensors. Five types of basic deformation are achieved including roll-up, roll-down, elongation, groove, and twist. Furthermore, a surface reconstruction method based on multisurface merging is proposed to describe the deformed surface of the robotic tongue quantitatively, which will be used in the surface-based motion control in the future. Motion tracking is carried out to verify the reconstruction results. The results of verification indicate that the proposed method is qualified to reconstruct the surface of the robotic tongue.