3D-Printed Artificial Cilia Arrays: A Versatile Tool for Customizable Mechanosensing.

Bio-inspired cilium-based mechanosensors offer a high level of responsiveness, making them suitable for a wide range of industrial, environmental, and biomedical applications. Despite great promise, the development of sensors with multifunctionality, scalability, customizability, and sensing linearity presents challenges due to the complex sensing mechanisms and fabrication methods involved. To this end, high-aspect-ratio polycaprolactone/graphene cilia structures with high conductivity, and facile fabrication are employed to address these challenges. For these 3D-printed structures, an "inter-cilium contact" sensing mechanism that enables the sensor to function akin to an on-off switch, significantly enhancing sensitivity and reducing ambiguity in detection, is proposed. The cilia structures exhibit high levels of customizability, including thickness, height, spacing, and arrangement, while maintaining mechanical robustness. The simplicity of the sensor design enables highly sensitive detection in diverse applications, encompassing airflow and water flow monitoring, braille detection, and debris recognition. Overall, the unique conductive cilia-based sensing mechanism that is proposed brings several advantages, advancing the development of multi-sensing capabilities and flexible electronic skin applications in smart robotics and human prosthetics.