The preparation and research of force sensitive characteristic of nano-scale FeNi powders/SiR film

This article adopted 60-100 nm FeNi powder as the stress sensitive source,silicone rubber for flexible substrate,and prepared composite films which the powders were distributed uniformity,powder content was 30.6wt%,and whose thickness was 200 microns.And the film force sensitive features with normal stress and integrated stress conditions were studied,under the conditions that the continuous load/unload speed was 0.1 mm/min,and test frequency was 1k Hz.The study shows that Nanoscale FeNi powders are distributed evenly in the film through excessive solvent liquid phase mixing method.Under the condition of normal stress,the sensitive precision of the thin film,i.e.-| k | value was greater than 50 when σ 0.2 MPa in the process of loading,while | k | value is between 37 and 49 when σ is 0.2-0.4MPa.In hence,the film is sensitivity to the normal stress that is less than 0.2 MPa.Under the condition of comprehensive stress,the value of sensitive precision of the thin film is more than 60,and the film is sensitive to the comprehensive when it is less than 0.1 MPa.Springback phenomenon of the thin film is obvious,leading that force sensitivity stability of the thin films is bad,When loaded/unload with complex stress.And the force sensitive feature of the thin film is better under the condition of normal stress than that loaded/unloaded under the condition of comprehensive stress.