A tactile sensor with the reference plane for detection abilities of frictional force and human body hardness aimed to medical applications

In this study, a novel tactile sensor with detection abilities of human body hardness and frictional force is reported. A new device configuration of back-side contact is proposed to realize a higher sensitivity of hardness, and low sensitivity to normal force. Miniaturization and sensitivity improvement of tactile sensor are important to apply the sensor to palpation inside of the body. Surface frictional force was successfully measured with rubber block in real time using our tactile image sensor. A completed device was evaluated, and shore A hardness was measured in the range from 1 HS to 54 HS. This performance corresponds to the hardness detection ability of adiposus in human body.