Ionic liquid based distributed touch sensor using electrical impedance tomography

Inspired by the human skin sensory mechanism, there are growing interests in creating a sense of touch in robotics. This work describes a new impedance based design to create an artificial tactile sensing skin. It has demonstrated that the electrical impedance tomography imaging technique allows for detecting the pressure distribution in a large area by a distributed touch sensor. The sensor is fabricated by filling a circular shaped phantom with liquid conductor and covering with an elastic shell on the top. The proposed sensor can detect the pressure applied to the elastic top using electrical impedance tomography imaging method. The sensor can therefore operate as a touch sensor mimicking a piezo-impedance operation in a simple fashion. The new sensor can differentiate between various force levels and their locations and thus produces a distribution of pressure. Such a simple sensor can function as a large area skin, enabling smarter human-machine interactions in emerging augmented reality and robotic applications.