Response Characteristics Of Strain Sensors Based On Closely Spaced Nanoparticle Films

Strain sensors have important applications in various fields of production,daily life,and scientific research.With the development of society and the advancement of science and technology,people have generated stronger demand of designing strain sensors with lower cost,lower power consumption,higher sensitivity,and stronger stability.In recent years,with the development of nanotechnology and nanotechnology,it has become possible to prepare flexible strain sensors that are lighter,thinner,and smaller in size and can be bent and applied to wearable devices.Flexible strain sensor devices were fabricated by depositing thin films of Pd nanoparticles on PET membranes patterned with interdigital electrodes.The sensors responded to the deformation of the PET membranes with the changes on conductance of the nanoparticle films and were characterized by both high gauge factor and wide detection range.The response characteristics of the strain sensors was found to depend strongly on the nanoparticle coverage,which was attributed to the percolative nature of the electron transport in the closely spaced nanoparticle arrays.By controlling the nanoparticle deposition process,a strain sensor composed of nanoparticle arrays with a coverage close to the effective percolation threshold was fabricated.The sensor device showed a linear response with a stable gauge factor of 55 for the applied strains from the lower detection limit up to 0.3%.At higher applied strains,a gauge factor as high as 200 was shown.The nanoparticle films also demonstrated the ability to response to large deformations up to 8%applied strain,with an extremely high gauge factor of 3500.At the same time,the article also compares the effects of different strain,different number of reciprocating bendings,different bending directions,different nanoparticle coverage,and other factors on the hysteresis,and concludes that similar to the stability of the sensor,the higher the sensitivity coefficient is,the more pronounced the hysteresis of the sample under the loss of external forces.The characteristics of elastic deformation of PET are the most important influence on the hysteresis phenomenon of the sensor,but through comparison,it is found that the nanoparticle lattice itself should also have a change in the deformation process that affects the performance of the sensor.