Basic Study on a Soft Tactile Sensor Based on Subcutaneous Tissue with Collagen Fibers

Humans have a high sensitivity and a broad receptive field in tactile function and the skin performs an important role to propagate mechanical stimulation to mechanoreceptors. Previously, a finite element analysis using a skin model with collagen fibers revealed that the collagen fibers disperse stress concentrations in subcutaneous tissue. Thus, this paper presents the development of a soft tactile sensor having a structure of the subcutaneous tissue composed of adipose tissue and the collagen fibers by using urethane resins. As a sensing element, the compression of the adipose tissue part occurred by deformation on the sensor's surface is measured by using the water level. A response of the proposed sensor is compared with a response of a sensor having a conventional uniform structure. The results indicate that the proposed sensor has a broad receptive field maintaining a high sensitivity as compared with the uniform sensor.