Characteristics of Flexible Pressure Sensor According to Circuit Configuration of MWCNTs/Polydimethylsiloxane Composite and Conductive Layer

When sensors were fabricated without a conductive layer, metal wires or pin headers were mainly used to receive the electrical signals from the sensor material. By fabricating the conductive layer, the degree of freedom in sensor design is increased and geometrically complex shapes can be manufactured. In this study, we built the electrical circuit for the flexible pressure sensor by arranging the multi-walled carbon nanotubes/polydimethylsiloxane composite and the conductive layer made from silver paste. That is, using DIW technology, the sensor material and conductive layer were formed into a series circuit and a parallel circuit, respectively, and the change in electrical resistance according to pressure was measured. As a result of experiments based on pressure, when the two materials were configured in a series circuit, they responded quickly to pressure at 35 ms. The changed resistance remained stable while pressure was applied. Consequently, the developed series circuit flexible pressure sensor demonstrates potential for applications involving instantaneous force or steadily increasing pressure measurement.