Preliminary Experiments Conducted on Prototypes of Sensitivity-changeable Soft Tactile Sensors Utilizing Phase Change*

This paper presents the fabrication and preliminary experiments conducted on two prototypes of sensitivity-changeable soft tactile sensors, which utilize the phase change of gallium between the solid and liquid states. Ordinal materials change their stiffness by the process of melting or coagulation, which leads to stiffness and sensitivity changes in the entire tactile sensor. We fabricated two types of prototypes, namely flat and dome-shaped sensors, created from silicone rubber, gallium, and strain gauges. The sensitivity of the former in the liquid phase is higher than in the solid phase. Conversely, the sensitivity of the latter is higher in the solid state than in the liquid phase. We performed preliminary experiments and confirmed that these tactile sensors are responsive to sensitivity changes.