Biocompatible, Transparent, and High-Areal-Coverage Kirigami PEDOT:PSS Electrodes for Electrooculography-Derived Human-Machine Interactions

Electronic skin sensors prepared from biocompatible and biodegradable polymeric materials significantly benefit the research and scientific community, as they can reduce the amount of effort required for e-waste management by deteriorating or dissolving into the environment without pollution. Herein, we report the use of polylactic acid (PLA) - a promising plant-based bioplastic - and highly transparent, conductive, biocompatible, and flexible poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) materials to fabricate kirigami-based stretchable on-skin electrophysiological sensors via a low-cost and rapid laser cutting technique. The sensor stack with PEDOT:PSS and PLA layers exhibited high transparency (>85%) in the wavelength range of 400-700 nm and stay attached conformally to the skin for several hours without adverse effects. The Y-shaped kirigami motifs inspired by the microcracked gold film endowed the sensor with attributes such as high areal coverage (∼85%), breathability (∼40 g m-2 h-1), and multidirectional stretchability. The sensor has been successfully applied to monitor electrophysiological signals and demonstrated with an eye movement-supported communication interface for controlling home electronic appliances.