Being able to cover the entire body of a robot with soft tactile sensors has become an attractive concept in intelligent robotics. Soft and stretchable materials can conform around surfaces and also absorb impacts, which is beneficial for safety considerations.
However, development of such a sensor is challenging and has not yet achieved to a satisfactory level. Large numbers of transducers must be placed on soft and stretchable substrates and then wired together. This can result in large wiring bundles, rigid elements and potential points of failure.
A geophysical imaging method called Electrical Resistance Tomography (ERT) has shown promising results and achieves large area-coverage, ease of manufacturability, and robustness. The ERT method is a reconstruction method estimating the internal conductivity distribution of a conductive medium by using boundary electrodes. These electrodes are used to inject electrical currents into the medium and measure resulting voltage potentials. The internal conductivity distribution is reconstructed from these measurements and calibrated to external pressures.
This project aims to develop a fabric-based tactile sensor to cover large-scale areas using the ERT method. To achieve this goal, we focus on two aspects. First, we develop a low-cost and reliable fabrication method. Fabric-based fabrication techniques are modified for this. Secondly, we focus on improvements of the sensing performance to overcome the limitations of conventional ERT-based tactile sensors. In this study, we will conduct optimization of sensor design and conductivity reconstruction techniques in order to improve tactile sensor capability.
The outcome of this study can provide a systematic method to develop whole-body tactile sensors for any type of robot.