Soil Mechanical Impedance Discrimination by a Soft Tactile Sensor for a Bioinspired Robotic Root

During the penetration into the soil, plant roots experience mechanical impedance changes and come into contact with obstacles which they avoid and circumnavigate during their growth. In this work, we present an experimental analysis of a sensorized artificial tip able to detect obstacles and discriminate between different mechanical impedances in artificial and real soils. The conical shaped tip is equipped with a soft capacitive tactile sensor consisting of different elastomeric and conductive layers. Experimental results show that the sensor is robust yet sensitive enough to mechanical impedance changes in the experimented soils.