| Flexible pressure sensor is a kind of electronic device used for sensing the size and position of the force on the surface of objects. It can be attached on any irregular surface. It obtains more and more attention for its broad application prospect in health, robotics, biomechanics, and other fields.In view of the present situation that the research and application of pressure sensors can not simultaneously meet the requirements of flexibility and accurate measurement of pressure distribution information, the innovative research on sensing materials, sensor unit, sensor arrays and automatic analysis system in this paper has been carried out. The major research content and innovation points are as follows:1. The pressure-sensitive material was made by mixing inorganic carbon black and organic silicone rubber. The performance of the materials needed, formulation and preparation method of carbon black/silicone rubber composite are studied,and pressure sensitive characteristics of carbon black/silicone rubber composite in DC and AC electric field is researched. The pressure sensitive characteristics of carbon black/silicone rubber composites in different ac frequencies were researched. The optimal frequency of the sensor is 1 K Hz. Microscopic mechanism models were put forward to analyze the positive pressure-resistance effect and negative pressure-capacitance effect, and then the positive pressure- impedance effect in AC electric field was explained. It was found that the sensor appeared higher sensitivity in ac electric field than that in DC electric field which has importance significance for the carbon black/silicone rubber composite2. An absolutely flexible pressure sensor based on flexible electrode substrate and piezoresistive rubber was designed. The electrode substrate material was PET/ITO(polyethylene terephthalate/ indium tin oxides), and piezoresistive rubber was carbon-black filled silicone rubber composite. In order to acquire the optimal sensitivity, the effect of conductive phase conte nt on resistance of carbon black filled silicone rubber composites was studied. The sensor showed positive pressure coefficient resistive effect under applied loading from 0 to 20 N(0-0.4 M Pa). Both the response time and recovery time of the sensor are less than 3 s.The sensor exhibited high sensitivity and fast response when implemented force be loaded or moved. The sensor is simple manufacture,low cost and suited for real-time detection.3. A 4×4 flexible pressure-sensitive array based on PET/ITO and piezoresistive rubber was designed and fabricated, with a size of 2.5 cm×2.5 cm×0.75 mm. The design effectively reduces the complexity of device structure. The array showed giant negative pressure coefficient of resistivity effect under 0- 4 N(0-0.32 M Pa). The pressure-sensitive array exhibited high sensitivity and fast response-recovery to loads. And the response and recovery times are less than 2 s. In order to easily and accurately recognize the sensitive size and azimuth of the applied loading on the pressure-sensitivity array, a detection circuit was designed and produced. The sampling data was analyzed and displayed by Lab VIEW finally. The basic performance parameters of the pressure-sensitive array were tested, the result shows that the pressure-sensitive array can realize the real- time pressure distribution. The pressure-sensitivity array is stable, low-cost and easy for fabricating large-area sensors. The designed micro array may be used in robot skin.
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