Evaluation of the Cross Talking Effect in Piezoresistive Tactile Sensor Matrices

Cross talking effects occur during measurements of sensor resistances in a two dimensional matrix. The cross talking current from neighborhood units influences measured values on the target sensor. This causes big systematic measurement deviations, especially for the piezoresistive sensors based on multi-walled carbon nanotube within Polydimethylsiloxane (PDMS). For this material, resistance value decreases significantly corresponding to the pressure value, which leads to large current increasing under the same excitation signal. In this paper, the cross talking effect is evaluated through the comparison between one usual data acquisition system and the data acquisition system equipped with voltage feedback circuit (VFC), which is suitable for the used nano-material. As result, it is demonstrated that voltage feedback method can eliminate the cross talking effect in the two-dimensional nano-composite sensor matrix. Meanwhile, the voltage feedback circuit cannot always remain high accuracy in extreme high resistance load range because of the non-ideal behavior of the hardware elements.