Morphology and Stretchability of Thin Film Metal Conductors on Elastomeric Substrates

摘要

Fabrication of biomedical devices and components on soft, elastomeric substrates is a promising step toward mechanically-matched and conformal biological-electrical interfaces. However, while polymeric substrates are extremely deformable, electronic materials typically are not. To explore this convergence of stiff electronic materials and compliant elastomers, we prepare thin film gold conductors on polydimethylsiloxane (PDMS) membranes (Fig. 1), which have Young's modulus, E ~ 2 MPa. The gold conductors have the property of remaining electrically conducting while stretched uni-axially to 20% strain and more [1]. Varying the fabrication methods affects the initial microstucture and morphology of the metal films, which in turn determine stretchability. To examine this effect, tensile tests are performed to measure electro-mechanical behavior, and scanning electron microscopy is used to observe the morphology of the films. In this study, we compare metal deposition techniques as well as samples of various metal thicknesses, linking resulting film morphologies to stretchability.