All-3D-Printed, Flexible, and Hybrid Wearable Bioelectronic Tactile Sensors Using Biocompatible Nanocomposites for Health Monitoring

Physiological signals contain a wealth of personal health information which needs continuous monitoring for early detection of disease-induced physiological irregularities and can be established as a potential approach to developing personalized healthcare devices. However, it is restricted by the lack of cost-effective, precise, sensitive, and biocompatible flexible wearable sensors that are rapidly, reliably, and cost-effectively are integratable. Here the work is reported on the development of novel, multimaterial, and multilayer all-3D-printed nanocomposite-based (M2A3DNC) microengineered, flexible, hybrid, and soft wearable pressure sensors to record sensitive and multiple physiological signals for real-time human health monitoring. By applying the intrinsic property of extrusion 3D printing, the conductive layers as well as the hemicylinder microstructure dielectric layer are directly 3D printed by optimizing the moving path of a nozzle, with air voids formation after assembling to enhance the compressibility of the active layer in our sensors. The microengineered sensors exhibit a very low detection limit, rapid response time, a repeatable and reproducible mechanical property with matching modulus with human skin (0.57-3.7 MPa) while offering intimate contact to the skin, excellent biocompatibility, and high mechanical compressibility in the active layer which leads to significantly high sensitivity. Thus, the proposed 3D printed cost-effective M2A3DNC sensors pave a novel path to develop a highly compressible microstructured device with high sensitivity and low detection limit in a time-effective manner with demonstrated application in real-time health monitoring and envision further applicability in robotics tactile sensing interfaces.