Effect of Hardness on Surface Strain of PDMS Films Detected by a Surface Labeled Grating Method

In recent years, mechanical properties of flexible materials have attracted much attention for the development of stretchable electronic devices, flexible sensors and wearable biointegrated devices that would support the future 'Internet of things' (IoT) and 'information technology' (IT). For designing advanced soft devices, there is a strong demand to quantitatively analyze the deformation behavior of soft materials. Recently, a surface labeled grating method has been developed as a new tool to quantitatively measure the bending behavior of flexible films. In this study, we investigated the effect of hardness of the film to be measured on the surface strain evaluated by this method.