An artificial skin from conductive rubber

Electrical impedance tomography (EIT) is a non-invasive technique that allows the detection and localization of impedance changes. By applying impedance tomography to a non-conducting rubber-base material filled with various densities of well-conducting carbon nanotubes, an artificial skin for robots can be envisioned, allowing to mimic in some sense the pressure dependent mechanoreceptors like Meissner’s or Pacinian corpuscles. The ultimate aim of this work is to provide a basic mechanoreceptor for small to medium forces of pressures that also allows to some extend the spatial mapping based on solving an inverse problem in impedance tomography. For this purpose a carbon nanotube filled synthetic rubber was used whose local resistivity is modulated via a locally applied force. The percolation theory provides the theoretical background of the functional dependency of resistivity vs. local pressure. The necessary electronics for the excitation of the electrodes and for the measurement was developed and the evaluation of the inverse reconstruction problem was implemented on a computer.