Development of Flexible Three-Axis Tactile Sensor Based on Screen-Printed Carbon Nanotube-Polymer Composite

Journal: Journal of Micromechanics and Microengineering (J MICROMECH MICROENG)

Abstract: A flexible, three-axis carbon nanotube (CNT)-polymer composite-based tactile sensor was presented. The proposed sensor consisted of a flexible substrate, four sensing cells, and a bump structure. A CNT-polydimethylsiloxane (PDMS) composite was produced by a solvent evaporation method, and thus, the CNTs were well-dispersed within the PDMS matrix. The composite was directly patterned onto a flexible substrate using a screen printing technique to fabricate a sensor with four sensing cells. When a force was applied on the bump, the magnitude and direction of force could be detected by comparing the changes in electrical resistance of each sensing cell caused by the piezoresistive effect of the composite. The experimentally verified sensing characteristics of the fabricated sensor exhibited a linear relationship between the resistance change and the applied force, and the measured sensitivities of the sensor for the normal and shear forces were 6.67％/N and 86.7％/N for forces up to 2.0 N and 0.5 N, respectively. The experiments to verify the load-sensing repeatability showed a maximum 2.00％ deviation of the resistance change within the tested force range.