Crosstalk-Free Impedance-Separating Array Measurement With Error Compensation for Iontronic Tactile Sensors

Iontronic tactile sensors are promising to measure spatial-temporal contact information with high performance. However, no suitable measuring method has been presented due to issues with crosstalk and nonnegligible equivalent resistance. Hence, this study presents an impedance-separating method, which does not require complex analog components or a continuous analog-to-digital sampling process. A general quadri-terminal impedance network (QTIN) model is introduced to reduce crosstalk. Based on a crosstalk visualizing platform, the features of concurrent iontronic measuring methods are analyzed, indicating specific merits between the QTIN model and the impedance-separating method. Then, a compensating method was presented to reduce the measuring error caused by temperature and scanning lag. The precise ranges are measured using standard components and compared with the theoretical error, which shows nonrectangle shapes suitable for the response of a homemade iontronic tactile sensor. A simple denoising method is provided to reduce initial array noise. Then, physical human-robot interaction (pHRI) information was analyzed, showing similarities and differences between capacitance and resistance features. For iontronic tactile sensors, this work realized crosstalk-free impedance-separating measurement, which could benefit various scenarios, such as human-robot interaction and physiological information monitoring.