Electrode-Shared Differential Configuration for Pressure Sensor Made of Carbon Nanotube-Filled Silicone Rubber Composites

To develop the differential pressure sensor made of carbon nanotube-filled silicone rubber composites with a simplified structure, an electrode-shared differential configuration is designed. The configuration includes the top and bottom sandwich layers. The top sandwich layer is composed of the top film, the intermediate film, and the composite film with low carbon nanotube content between them. The bottom sandwich layer is composed of the intermediate film, the bottom film, and the composite film with high carbon nanotube content between them. The electrode in the intermediate film is shared by the top and bottom sandwich layers, which can make the sensor probe more concise. The electrical resistance of the composite film with high/low carbon nanotube content increases/decreases with the increase of the pressure, and increases with the increase of the temperature. The top and bottom sandwich layers are connected to the neighboring arms of an electrical bridge to construct a differential system. The experiments verify the feasibility of using the electrode-shared configuration to construct the differential piezoresistive sensor made of the composite to decrease the temperature-induced drift and increase the sensitivity.