Waving Tentacles

When we see the wriggling movement and the shape of a tentacle like the sea anemone under the sea, we feel an existence of a primitive life. The goal of this research is to realize the expression of a kinetic artwork like waving tentacles of sea anemones by robotics. Previously, we have created two pieces of art, “Himawari” and “plant”, using a shape-memory alloy (SMA) actuator driven in one direction. In this research, we introduce a new SMA actuator that can bend in three directions. At present, soft actuators bending in multi directions is developed in several areas. For example, there is a medical active catheter, a microrobot mimicking annelid animals and animatronics. However, these have a complex structure or are expensive. To realize the expression of waving tentacles needs a large number of actuators (e.g. over one thousand actuators). Therefore, we developed a budget actuator with a simple structure.


The SMA actuator driven by three Biometal Fibers (BMF150, developed by TOKI Corporation) can bend in three directions. The heat of each Biometal Fiber is controlled through a pulse-width modulation voltage. The SMA actuator behaves in three motion patterns. The top of SMA actuator is illuminated by the optical fiber connected to the LED.




We believe a larger number of actuators will allow presentation of expressions that are easier to understand. In the future, we will develop a system with over one thousand actuators and interactive functions. Applications include interactive walls, digital signage using visual expressions, moving dolls in theme parks and a music visualizer.

This work was supported by JSPS KAKENHI Grant-in-Aid for Scientific Research(C) 26330418.

International Conference :
Nakayasu, A. 2014. Waving Tentacles: A System and Method for Controlling a SMA Actuator. In SIGGRAPH 2014 Posters, ACM.