Developing tactile sensors for a soft-bodied robot

Two types of tactile sensors were developed to detect normal contact for a soft bodied robot inspired by octopus. The first type was fabricated using quantum tunnelling composite (QTC) materials. Under pressure, the material transforms from an insulator to a conductor. Electrolycra was used to connect the QTC pills to wires. The second type of sensor was fabricated using a silicone rubber plate with a hole at the centre sandwiched between two electrolycra sheets. Under contact load, the two electrolycra sheets come into contact and the resistance of the sensor reduces significantly. As both silicone rubber and electrolycra have high elastic strain limit, the second type of sensor is also highly extensible. Sensitivities of the sensors were tested by applying different modes of loading and the soft sensors were incorporated into the skin prototype. An integrated skin prototype with embedded deformable sensors is also presented.