The authors have proposed a method for detecting a friction coefficient between a planar object and an elastic finger-shaped sensor by only pressing the sensor against the object in our previous study. In the present study, an elastic finger-shaped sensor made of silicone rubber is designed and produced. First, geometry of the finger-shaped sensor is designed using finite element analysis (FEA). Results of FEA revealed that strain detected using strain gage incorporated near the edge of the contact surface varies when the friction coefficient between the finger-based sensor and a planar object varies. Then, in a experiment using the newly designed sensor, it is confirmed that the friction coefficient between the finger and the object is detected using the strain inside the finger when the sensor is pressed against the object.