Stretchability of flexible electronic composite films attached to simulated skin
In order to evaluate the stretchability of flexible strain sensors on human skin under different conditions,a flexible electronic composite film embedding a horseshoe-shaped metal wire in a PDMS substrate was fabricated.A two-component silicone rubber with the Shore hardness of 10 was served as the simulated skin for ex vivo experiments.The displacement and Von Mises strain fields during the sample deformation on the simulated skin of different thicknesses were captured using the Digital Image Correlation(DIC)method.The evaluation indexes,mean value M and elongation at break e were proposed.The impact of the skin thickness and ambient temperature on the stretchability was analyzed.The results demonstrate that both factors significantly influence the stretchability of the composite film.Notably,a 2 mm skin thickness and 40 ℃ result in the optimal stretchability,with the elongation rates of up to 145%.These findings provide valuable insights into the design of the flexible strain sensors,specifically in terms of the strength requirements.
flexible electronic composite filmdigital image correlationsimulated skinstretchabilityelongation at break