Additively Printed In-Mold Electronics Circuits and Sensors and Process-Performance Interactions for Automotive Applications

The emergence of additively manufactured electronics has made it possible to integrate safety features into automotive touch surfaces for the assessment of driver alertness and state of stress. Current touch surfaces in vehicles are mainly for aesthetics, but integrating human-machine interfaces through additively printed in-mold electronics is a potential advancement. The processes for printing sensors and integrating surface mount electronics for signal processing in additively printed conformal electronics are still unknown. In-mold electronics provide additional opportunities for the elimination of wire harnesses and lightweighting of the vehicle to meet stricter CO
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emission standards and reduce carbon footprint. This paper investigates direct ink write, and gravure offset print processes for thermoformed in-mold electronics on diverse substrates. Surface mount component attachment is explored using conductive adhesive and creating signal processing and electrodermal sensors for measuring galvanic skin response, useful in assessing driver emotions and health. The study aims to establish fabrication guidelines for in-mold electronic circuits, including ink print parameters, curing times for ink and adhesive, and thermoforming parameters for optimal electrical performance and mold conformity.