Research On A Functional Flexible Sensor

With the development of the information society and the continuous progress of the Internet of Things technology,the depth and breadth of people's collection of environmental information continue to improve.Conventional sensors may cause problems such as poor signal transmission quality due to their own rigidity.In contrast,flexible sensors capture target analytes more efficiently and produce higher quality signals because of their compatibility with any moving parts or surfaces.Flexible sensors have broad application prospects in the fields of robotics,biomedical,wearable devices,implantable health testing equipment,and human-computer interaction.In this paper,polydimethylsiloxane(PDMS)and silver particle powder were used to prepare an ultrasensitive,printable,multimodal and high conductivity Ag-PDMS elastomeric polymer film.The Ag-PDMS conductive film and the PDMS film were bonded and packaged into a flexible sensor by plasma cleaning technology.The innovation of the process described in this paper is that the preparation process has the characteristics of not involving any dangerous chemicals(such as strong acid and alkali),simple preparation process and low time consumptionIn this paper,the properties of Ag-PDMS films were analyzed by tensile test.The maximum tensile rate of Ag-PDMS films is 50%,and the sensitivity(defined as the ratio of film resistance to tensile rate)can reach 939,which is greater than the sensitivity of all flexible sensors made from the same type of materials.The structure and sensing mechanism of Ag-PDMS films were analyzed by scanning electron microscopy(SEM)images.With the increase of the filling amount of silver particles,the larger the proportion of the distribution area of silver particles in the PDMS substrate area,that is,the larger the conductive path in the film,the better the conductivity of the film.When the film is subjected to external force,the distribution of silver particles is no longer dense.The conductive path is destroyed,andthe resistance of the film increases.After the external force disappears,the silver particles inside the film are subjected to the elasticity of the flexible substrate,and the conductive path returns to the initial state.In this paper,the practical application of flexible sensors is verified.The sensor can quickly and sensitively detect the bending-extension movement of index finger.The response time of the sensor is within 0.174 s.And the peak resistance change rate is 3.75 which is the highest reported in the flexible sensors for the same type of physiological monitoring.The flexible sensor can also sense the external sound intensity,and the sensed minimum sound intensity is 49.44 dB.Through these two practical applications experiments,it is vertified that the flexible sensor has broad application prospects.