Additive Manufacturing of Graphene-Based Wearable Pressure Sensors Via Direct Ink Printing

The rapid growth of wearable technologies and biomedical monitoring systems has substantially increased the demand for highly sensitive, reliable, and cost-effective pressure sensors. Among the various sensing mechanisms, resistive pressure sensors are particularly attractive because of their high sensitivity, simple readout circuitry, and ease of fabrication. In this work, we report on the additive manufacturing of a graphene-based flexible force-sensing resistor using direct ink printing. The sensor consists of two flexible polyethylene terephthalate substrates separated by a spacer frame, with two interdigitated electrodes printed on the top substrate and a graphene-based resistive layer deposited on the bottom substrate. This approach enables precise, repeatable, and scalable fabrication of electronic patterns, making it suitable for large-scale manufacturing. Moreover, the graphene-based resistive layer enhances resistance changes under applied load, thereby increasing the sensitivity. The fabricated sensor is cost-effective and straightforward to manufacture, and it can detect forces from a few newtons up to 100 N, with a sensitivity of 11.28 ΩN-1. In addition, it exhibits ultrafast response and recovery times of 150 microseconds and 250 microseconds, respectively, making it promising for a broad range of applications.