Scalable Microfabrication of Folded Parylene-Based Conductors for Stretchable Electronics

Abstract

Electronics implemented on biocompatible ultrathin substrates like polyethylene terephthalate, polyimide, or parylene enabled a wide range of conformable, lightweight smart wearables and implantables. However, applications in such dynamic environments require robust devices that adjust and stretch while maintaining their functionality. Universal approaches that unite scalable, low-cost fabrication with high performance and versatile, space-efficient design are sparse. Here, stretchable architectures of parylene enabled by Origami-inspired folds at the micrometer scale are demonstrated. Parylene is directly deposited onto anisotropically etched silicon molds to greatly reduce bending stress, allowing folds with bending radii of a few micrometers. 50-nm-thick gold conductors fabricated on the folded parylene facilitate electronics with a stretchability of up to 55% tensile strain. The conductors sustain a resistance below 20 Ω during reversible stretching of more than 10 000 cycles, enabling long-term operation in practical settings. This method presents a versatile tool for the microfabrication of stretchable devices with tunable properties.